CA2369390C - Monitoring device for vacuum cleaner - Google Patents

Abstract

There is described a central vacuum cleaning system comprising: a flexible hose having a first end terminating in an air inlet means and a second end terminating in an air duct connector for connection to an air duct, a handle portion having a control switch, and two conductive wires extending inside the flexible hose from the control switch to the air duct connector; a status indicator on at least one of the handle portion of the flexible hose and an inlet of the air duct; and a central vacuum power unit connectable to the air duct and comprising a motor for powering the system, a filter for filtering incoming air, a dirt container for receiving dirt from the filter, a pressure sensor operatively connected between a cleaned air side of the filter and the dirt container, and a control module connected to the pressure sensor and adapted to send a first signal to the status indicator when a measured pressure exceeds a predetermined pressure threshold, thereby indicating a maintenance need.

Description

MONITORING DEVICE FOR VACUUM CLEANER
FIELD OF THE INVENTION
The invention relates to centralized vacuum cleaning systems and more particularly to a centralized vacuum cleaning system monitoring device allowing to indicate to the user of the system, of any maintenance required on the power unit in order to maintain high cleaning capability of the system related in particular to the possible partial clogging of the filtration mean and to preventive maintenance in order to get a long term performance of the central vacuum system.

BACKGROUND OF THE INVENTION
A central vacuum cleaner comprises a power unit usually installed permanently in an area of a building and one or more ducts are connected to vacuum system inlets provided in various zones all over said building. Said cleaner allows to clean any areas of said building with the use of a flexible hose or other debris recuperation device connected to said inlets. Said central vacuum power unit can be activated by mere insertion of the hose in one of said inlets which is electrically wired to said unit, or by a switch provided on the hose or in the debris recuperation device or by any other means.
There are 4 significant advantages to a central vacuum system. The following shows some example of possible advantages:

1- The available power output of a central vacuum system is generally higher than a portable system. The fact that we do not have to move the whole power unit in a centralized vacuum system allows for the use of bigger and stronger motors and also the use of greater dimensioned filters resulting in higher airflow power output.

2- With a central vacuum system, there is no need to move a cumbersome machine that can hit and make an object in the way of the machine's moving path fall, as this is often the case with portable systems.

3- Another advantage is that a central vacuum system easily allows for an evacuation of the working air outside the building, avoiding any possible recirculation of air that could still contain very fine dust particles into the building.

4- Noise level perceived is normally lower than the noise level from a portable vacuum since a central vacuum power unit is often located in a remotely located area of the building (for instance: in the basement). In a portable system the motor unit is generally relatively close to the user so the noise level would be comparatively higher.
Because the central vacuum power unit is generally located in a remote area of the building that is often not the same area where the cleaning work is performed, then it is compulsory for the user to go near the power unit if he wants to see the state of the system, unless a method of sending information to the user is provided. The most preferable way of sending the said information to the user is to have a perceivable signal transmitted directly from the hose handle. This could be done by a light, sound, vibration or any other means.

Prior art shows that information on the hose handle is available most particularly for portable vacuum cleaners. But since the hose length of a portable vacuum cleaner is relatively short compared to the hose and duct length of a central vacuum system, and also that the hose on a portable vacuum cleaner is not located in the walls of the building, it is relatively easy to manufacture multiple (more than two) conductor wires in the hose of a portable vacuum cleaner. This is relatively not as easy in a central vacuum system since a power unit is often installed in an existing building installation using the standard 2 conductor wiring normally running along each duct that leads to the valve inlets of the system. Economically, two conductor wires are generally used throughout the industry of centralized vacuum systems. Often, some builders install all the piping and as a standard, a 2 conductor wire, giving the future owner of the building or area of the building the possibility of choosing his own central vacuum power unit.
This being said, it would be difficult to install different wiring after all the wall finishing is done, selected paint is applied etc... This fact known, a central vacuum power unit that could transmit a variety of useful information to the user up to the hose handle area, using the industry standard two conductor wire would mean a significant advantage.
From prior art, systems for indicating the state of a central vacuum power unit have demonstrated to be generally complicated systems, often using lots of electronic components in the hose handle which is subject to vertical impact on the floor from a height of over 3 feet high for example. As this impact or condition can happen often in the life of a central vacuum system hose handle, it is mathematically more likely to fail, showing here the need for simple and rugged characteristics for a said indicating device system.

One of the most important things to monitor in a central vacuum system for effective cleaning performance of a determined system is the state of clogging of the filter. There is also a need for a system that would be able to transmit to the user the information relating to the maintenance of motor components of the central vacuum power unit in order to assist the user and/or owner of the central vacuum power unit in doing preventive maintenance. A regular preventive maintenance is known to avoid costly repairs in all mechanical products. So an integrated signal reminding the user that it is time for preventive maintenance is considered very useful in combination to the indications related to clogging of filtration means and together contributes to maintain long lasting performance of the system. In prior art related to vacuum cleaners, various methods are found. Some methods use electronic circuitry programmed as a function of each motor used which takes into account the rotational speed of the motor and/or drawn current. These methods can work to some extent but they tend to be complicated, costly to manufacture and also more subject to failure, mathematically speaking due to their degree of complexity.

SUMMARY OF THE INVENTION
It has now been discovered that it is possible to send multiple information from a central vacuum power unit to the hose handle using only 2 distinct wires of electrical cable (i.e.
2 channel), while having a very limited number of components in the hose handle (basically a Bicolor LED plugged in a series arrangement), thus showing to be a very robust and reliable way to transmit information to a user of a central vacuum system distant from the central vacuum power unit. Also, it has been discovered that this information sent from the power unit can be constant, or even a blinking signal without affecting the power unit motor from working simultaneously.

In accordance with an aspect of the invention, there is provided a central vacuum cleaning system comprising: a flexible hose having a first end terminating in an air inlet means and a second end terminating in an air duct connector for connection to an air duct, a handle portion having a control switch, and two conductive wires extending inside the flexible hose from the control switch to the air duct connector; a status indicator on at least one of the handle portion of the flexible hose and an inlet of the air duct; and a central vacuum power unit connectable to the air duct and comprising a motor for powering the system, a filter for filtering incoming air, a dirt container for receiving dirt from the filter, a pressure sensor operatively connected between a cleaned air side of the filter and the dirt container, and a control module connected to the pressure sensor and adapted to send a first signal to the status indicator when a measured pressure exceeds a predetermined pressure threshold, thereby indicating a maintenance need.

In one embodiment, the control module also comprises a timer for monitoring the activity time of the system, and the control module is adapted to send a second signal to the status indicator when time elapsed since a last reset action exceeds a first predetermined time threshold.

Components of the system:
In the flexible hose handle: These components are found in the hose handle:
One bi-color LED, one switch, and two wires coming from the flexible hose.

In the central vacuum power unit: Control module on the information available in this document in addition to known ways in the prior art to manufacture central vacuum power units (i.e. motor, fan, seals, etc.).

Link "power unit- hose handle" : Two conductor wires in the flexible hose linking electrically the valve wall inlets to the switch & LED present in the hose handle.
Advantageously, the present invention relates to a new central vacuum monitoring device.

Advantageously, the indicating device will be installed on the flexible hose handle but could be installed only on the valve vacuum inlets present in various areas in the building.

Advantageously, the signal will be given to the user directly from a signal coming from the hose handle.

Advantageously, the signal given will be visual.

Advantageously, the visual information will be transmitted by a Bi-color type LED.

A sensorially perceivable monitoring indicator can be a visual indicator such as Bi-Color LED or any other suitable means.

Advantageously, the color obtained from the LED could be perceived has red or green or amber.

Advantageously, the signal would be present on both the central vacuum power unit and on the hose handle.

BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects and advantages of the present invention will become better understood with regard to the following description and accompanying drawings wherein-FIG. I is a plan of the main circuit board in accordance with a first embodiment of the present invention, FIG. 2 is a plan of the daughter board in accordance with the first embodiment of the present invention, FIG. 3 is a schematic illustration of a flexible hose in accordance with the first embodiment of the present invention, FIG. 4 is a partial perspective view and partly sectioned of a central vacuum system unit, without the cover and the canister walls.
Fig. 5 is a schematic transversal view of FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
IPM system (Intelligent Performance Monitoring) The main purpose of this new electronic module is to help the user in maintaining the performance of his central vacuum system. The help in the maintenance is divided in two aspects:

1. Short term maintenance:
That includes a way of monitoring.-- A differential pressure sensor monitoring functionality in order to get information about the state of clogging of the filter.
- A timer functionality monitoring time elapsed since a last reset of the 15hrs functioning time. The basic reason for this 15 hours being the need to empty the debris receptacle based on manufacturer experiences.

2. Long term maintenance:
- A timer functionality monitoring time elapsed since last reset of the 490 hrs &
500hrs functioning time. Essentially related to preventive maintenance of the electrical motor in the power unit.
The intent of the pressure differential monitoring is to be able to tell the user of the vacuum of the decreased performance of the central vacuum system ideally before the user notices the degradations in performances due to habituation (not noticing degradation of performance due to the slow process of degradation in performance).
However, when the user will go clean his filter he should note that after cleaning, the performance of his machine has significantly increased. This operation will show to be useful since the result will be more a efficient central vacuum system that should allow the user to perform the cleaning task faster since more power is now available from the system.

Figures 4 is a partial perspective view, and partly sectioned, of a central vacuum power unit 400, without the cover and the canister walls. Fig. 5 is a schematic transversal view of FIG. 4. A filter 402 is inside the power unit 400. A pressure sensor 404 is connected to an electronic module. One tube 406 of the pressure sensor 404 is connected to a dirt laden vacuum air side of the filter (outside). The other tube 408 is connected to the cleaned vacuum air side of the filter (inside).

IPM Features 1. Power motor control:
As illustrated in figure 3, using the reliable relay technology, it is possible to turn ON/OFF the vacuum motor remotely from the switch 300 located in the hose handle 310 and wired through the piping with two standard low voltage wires 302. A
daughter board, as illustrated in figure 2, with bicolor LED 304 (BLED) and a tiny push switch 300 (reset/demo) is included as part of this module.

2. Low voltage LED Autopolarity:
In addition of the switch 300 located in the hose handle 310, there is a light emitting diode (LED) 304 used to indicate the motor status, so this LED 304 will light green, red, amber and/or blink at different speed showing the actual status.
But no matter how you connect the Low voltage wires (LVW) 302 in the central vacuum (CV) or how is it wired through the hose 308, this LED 304 will always show the right color.

3. Hi vacuum detection:
If abnormal high vacuum is detected (differential pressure above 40 inches H2O), the LED and BLED will blink amber (2 /sec).

4. Timing record:
By using the EEPROM technology (Non volatile memory) the control board records two types of timing. The user can check them any time by looking at the BLED:
a. Partial time, the BLED blinks slow no matter the color.
b. Total used, the BLED changes color.
Time used BLED color Meaning Action to be taken 15 hours Slow blink The vacuum has Clean the bag and been used for at reset by holding this least 15 hours after switch for 5 seconds resetting 490 hours Red /10 secs The vacuum has Preventive Accumulated Green / 20 secs been used for more maintenance than 490 hours 500 hours Blink Red The vacuum has Priority to perform Accumulated 2.5 sec been used for more maintenance than 500 hours Table 1 5. Self test:
When just connecting the board to the AC line, the board performs a self test, if everything is OK the BLED blinks fast green for a few seconds.

6. Reset/demo switch:
This switch does the following:
Function Action Results Test/demo Push and release for no The system performs a self more than 5 seconds when test, so the BLED will light the motor is OFF or ON through all states (see table 1) Partial reset push and hold for more The, system will reset the 15 than 5 seconds when the hours timing, if the system motor is OFF was blinking the current color becomes solid Total reset Push and hold for more The system will reset the than 30 seconds when the accumulated hours motor is ON recorded Table 2 7. Night light compatibility:
If desired, it is possible to connect standard LEDs in series) (no matter the polarity) to perform the nightlight feature, no need for an adaptor or similar power supply.

8. Old system compatibility:
The system can work with the old style CV hose, for example, when using a standard hose the system will work by short-circuiting the LVW.

9. Customizable features:
Because the system is software based, it is possible to customize the timing (BLED colors, delays, etc.).

Detailed explanations of respective status levels:

Level 0 No LED on the (optional) hose handle or on the unit The power cord of vacuum is not plugged in electrical outlet.

Level 1 Fast blinking green on the unit The power cord of the vacuum has just been plugged in the outlet or after the resetting of Level 4.

Level 2 Constant green on the unit only The power cord of the vacuum is plugged in the electrical outlet, but the switch on the hose handle is off or the hose is not inserted in the valve.

Level 3 Constant green on the (optional) hose handle or on the unit The system is remotely activated the vacuum is functioning. In order to always have high efficiency of your unit and to maintain the unit properly, it is highly recommended that you always use your vacuum at Level 3.

Level 4 Slow blinking green on the (optional) hose handle or on the unit 15 hours of use have passed since last reset; this indication recommends to empty the dust container of your unit. After emptying the dust container, always push and hold the IPM reset button until the LED starts fast blinking green and then release.

Level 5 Slow blinking amber on the (optional) hose handle or on the unit This indication suggests that you should clean the filter & empty the dust container in order to maintain the high performance of your unit. The IPM
basically detects whether the filter is obstructed enough to hamper the proper performances of this unit. Resetting the IPM is not required. The IPM sensor detects the differential in vacuum by the use of 2 independent sensor tubes connected on each side of the filter.

Level 6 Constant red on the (optional) hose or on the unit This programmed indication for 10 seconds every 30 seconds, recommends that you have your unit inspected by a qualified technician in order to prolong the life of the motor. This indication will appear after 490 hours of usage.

Level 7 Fast blinking red on the (optional) hose or on the unit (for 10 seconds every 30 seconds) This is an extension of "Level 6" this routine indication highly recommends that you have your unit inspected by a qualified technician to prevent damage to the motor. This indication will appear at 500 hours of use. (As an indication, this is, for an approximate use of 1 hour a week, equivalent to about 100 years).

General Overview of the preferred embodiment The power Control Modules (PCM) MC-xM and MCE-xM were designed to work as a Vacuum cleaner power control, their performance is the same, the difference is the 220-240 transformer and the filter. So for the European version, there is a transformer and EMI filter, but the North-American version has only a 110-120 transformer. The secondary in both versions are the same: 9 VAC and 24 VAC.

The PCM has two boards: Main board (figure 1) and daughter board (figure 2).
In the main board are located all the power components. In the daughter board only the extra low voltage electronic components are used for control, supervision and interface.
Since the main board does not show particular interest in respect to the related invention presented here, only the description of the daughter board will follow.
However, we can say that information is transferred form the daughter board throughout the flexible hose by passing by the main board.

Daughter board This board has two main components:
The 8-bit micro-controller 200 (uC) PIC12CE673 with A/D converter, 3 timers, EEPROM
memory and 6 independent & configurable I/O ports 202 (P to P5). Its software is able to convert the incoming Analog and Digital signals and based on programming and historic parameters, make a decision to produce a digital output signal to drive the power and LED components through their drivers.

The operational amplifiers 204a-204d are 4 gates for a single power supply.
These OPAmps with their associated components use 2 gates to drive the external Low Voltage Wires (LVW) and two to monitor them (get feedback).

There are also some other components that are worth the mention like the Transistor 206, the LED 208 and the Voltage regulator 210. These components are used respectively to drive the relay (main board), to show the status in three colors and to maintain a stable VDC to power the electronics.

How does it work Please refer to Daughter Board schematic (figure 2).

When the appliance is plugged-in what happens electronically:
1. When the appliance is connected, the uC 200 is energized and does the following:
a. Turn OFF the monitor ( P5 ) b. Measures the AC line frequency through P3 c. Verify, read and update the timing from the EEPROM memory d. Autocheck all the inputs/outputs and activate the watch-dog feature e. Start scanning the LVW through 204c & 204d. That means it changes the polarity every 8 mSEC. Because 204a-204d are powered by 24VDC, the LVW
will be 24 VAC @ 62.5Hz If everything is OK, the LED on the PCN blinks twice ( ports PO and P2 ).
When the appliance is plugged in and the hose is plugged in the valve of the system, what happens electronically when the LED becomes constant green (Power on condition ):

2. When a bicolour LED (BLED) is connected remotely through the LVW, it is detected by 204c and 204d, then by changing the LVW polarity through 204a and 204d, the uC
200 detects how it is connected to the BLED and what color is displayed. If it is the wrong color, it corrects the polarity. This detection is made fast, however, to avoid false detection, and the system verifies many times before taking the signals as correct.

The LVW are driven through two 620 ohm resistors (212 and 214) which protect 204a-204d from over current and limit the LVW current to 20 mA.

When the appliance is plugged in and the hose is plugged in the valve of the system, what happens electronically when the LED becomes constant green (15 hrs condition):
3. Every second is recorded by EEPROM if the vacuum motor is energized, so when the uC 200 detects 15 hours accumulated it makes both LEDs (on hose and on PCM) blink. The local LED is made to blink by turning ON/OFF PO and P2, and the one on hose is made to blink by turning ON/OFF PO and P1 the drivers (204a and 204b).

When the appliance is plugged-in & the hose is plugged in the valve of the system & the pressure switch detects a pressure higher than a predetermined setting, what happens electronically when the LED slowly blinks amber (differential pressure condition):

4. The Hi vacuum condition is detected by a electro-mechanic component located in the main board. It is normally open, so when it closes, this condition is detected by P3.
Before any LED starts blinking, the uC 200 filters this signal to avoid false conditions. By changing the polarity of both the LED 208 the uC 200, the color shown is changed to amber. Actually there is no amber, like television it comes from the combination of red and green, so the 8 mSEC period is divided 70% green and 30% red. But the human-eye persistence combines these two colors in order to perceive an amber color.

When the appliance is plugged-in & the hose is plugged in the valve of the system & the elapsed time since a last maintenance has reached a predetermined setting of 490hrs, what happens electronically when the LED becomes a constant red (490hrs condition):
5. When the uC 200 detects the accumulated time has reached 490 hours, it changes the polarity on both LEDs to light the red color.

When the appliance is plugged-in & the hose is plugged in the valve of the system & the elapsed time since a last maintenance has reached a predetermined setting of 500hrs, what happens electronically when the LED becomes a fast blinking red (500hrs condition):

6. The same as above but for 500 hours. In this case the blinking is made faster by changing the duty cycle ON/OFF.

When the appliance is plugged-in & the hose is plugged in, what happens electronically in order to be able to get a DEMO mode for the module:

7. The push switch located on the daughter board is monitored by P1 (working as input), so after being digitally filtered by the uC 200, if the switch has been pushed for more than 5 seconds, the uC 200 interprets it as a test/demo status and starts an internal routine that injects internal signals to test all software and hardware. This way the system has to pass all the events that it was programmed for. As a result all the colors and blinking combinations are shown.

How does the automatic detection of polarity work in this module:

8. The OpAmp gates 204c and 204d and fast diodes D3 and D4 are polarized symmetrically to amplify and detect small DC differences in the LED connected on the LVW. This way the signal injected to the uC through PO is always positive.
This signal is digitized, filtered and compared with pre-programmed parameters to keep the right color. Again, as mentioned above the signal is filtered to reject noise coming from or around the LVW.

This type of design involves the relationship between hardware and software, this was completed using the most recent advances in the technology.

Other advantages of the system:
The simple fact of having an intelligent module:. Generally the central vacuum power units available in this industry are manufactured without an intelligent module. So the sole fact of having such a module represents an advantage.

The information is available preferably on the hose handle: The fact that the information is available directly on the hose handle and is far from the power unit makes it unnecessary to go see the information directly on the power unit, and it allows information on the status of the system without delay.

Only necessary information is transmitted: This system will not transmit unnecessary information to the user. If the status light on the hose handle changes, it means that there is a requirement for action from the user. This prevents the user from getting confusing information from the system.

Minimal quality of components in the hose handle: Allows for more economical and reliable system.

Only a two conductor wire is used for bi-directional communication: Our invention only needs 2 wires in order to be able to communicate multiple information to the user. The same wires are used to transmit control information from the user to the central vacuum power unit. Even blinking signals can be sent to the user without affecting the performance of the motor unit.

Indications given by the system are intuitive and essentially recognized worldwide: The LED advantageously present on the hose handle show strong similitude with ones used in transportation circulation indication which is quite well recognized worldwide.

Transportation circulation Indication from IPM
(control module Green You can go You can go Amber For security, it is For better performance, it suggested to stop if you is suggested to stop and can go clean your filter/debris canister Red You need to stop to You need to stop to prevent damage prevent damage Also: A slow blinking refers to a not so urgent thing to do, while a fast blinking refers to an urgent thing to do.

It is possible to activate the DEMO of possible indications given by the system: This is a really significant advantage when presenting the central vacuum power unit to a new customer. The consumer then knows and sees exactly how the information will be given to him during the use of his future machine. This advantage is particularly good during commercial presentation of the product to a potential new customer.

Easy Integration of an Intelligent system to an existing ducting and wiring Installation: It is possible thanks to this invention, to easily integrate an intelligent control module to an existing building where all ducting work and electrical wiring has been done without any modification to the piping and wiring usually nested into walls of the building. This proves to be particularly useful considering that otherwise a much more complicated and/or inconvenient and/or costly solution would have to be put in place in order to "patch" the problem (opening the wall, seeing an apparent outside cable in an elegantly crafted room).

Easy reset of the timer is allowed by the use of this system : Compared to some other central vacuum manufacturers that will ask to replace the whole control module when a preset time is reached, ours just needs to be reset by the simple push of a button present on the central vacuum power unit. This proves to be a significant advantage since it is simple and NOT a costly operation. The same reset button is used for the 15 hrs reset and for the 490 hrs and 500 hrs reset timer.

No decision to control the machine for the user: The module is preferably just an indicating device. So the electronic module would never take the decision of shutting down the motor, an indication will recommend the user to do so, and the final decision to take action will be his.

The fact of combining pressure sensor and timer: This offers 4 significant advantages:

- Prevent long propagation of bacteria, molds, etc Do to too much time between cleanings of the system.

- Prevent overflow of debris tank if a lot of big low density particles are vacuumed (based on experience this 15 hrs time is adequate).

- The fact of not having just a pressure sensor but a timer for preventive maintenance allows to maintain not only short term performance but to maintain performance over the years of use of the central vacuum system equipped with the invention presented in this document.

- Since there is a 490 - 500 hrs timer included in this invention, it is not mandatory for the user to write down on a separate sheet of paper a reminder to remind him when the last inspection of his power unit was done. Furthermore, he does not even have to bother to evaluate the time when his power unit will have reached 500 hrs of use since the object of this invention does it for him.

It will be understood that numerous modifications thereto will appear to those skilled in the art. Accordingly, the above description and accompanying drawings should be taken as illustrative of the invention and not in a limiting sense. It will further be understood that it is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features herein before set forth, and as follows in the scope of the appended claims.

Claims (9)

1. A central vacuum cleaning system comprising:
a flexible hose having a first end terminating in an air inlet means and a second end terminating in an air duct connector for connection to an air duct, a handle portion having a control switch, and two conductive wires extending inside the flexible hose from the control switch to the air duct connector;
a status indicator on at least one of the handle portion of the flexible hose and an inlet of the air duct; and a central vacuum power unit connectable to the air duct and comprising a motor for powering the system, a filter for filtering incoming air, a dirt container for receiving dirt from the filter, a pressure sensor operatively connected between a cleaned air side of the filter and the dirt container, and a control module connected to the pressure sensor and adapted to send a first signal to the status indicator when a measured pressure exceeds a predetermined pressure threshold, thereby indicating a maintenance need.

2. The central vacuum cleaning system of claim 1, wherein the control module also comprises a timer for monitoring the activity time of the system, and the control module is adapted to send a second signal to the status indicator when time elapsed since a last reset action exceeds a first predetermined time threshold.

3. The central vacuum cleaning system of claim 2, wherein the control module is configured to keep at least two separate timer counts, a first timer count corresponding to the time elapsed since a last reset and a second timer count corresponding to a total activity time of the system, and to send a third signal to the status indicator when a second predetermined time threshold has been exceeded by the total activity time of the system.

4. The central vacuum cleaning system of claim 3, wherein the second timer count is also used to send a fourth signal to the status indicator when a third predetermined time threshold has been exceed, the third predetermined time threshold being greater than the second predetermined time threshold.

5. The central vacuum cleaning system of any one of claims 1 to 4, wherein the status indicator is a light provided on the handle portion of the flexible hose and the light flashes or changes color when a signal is received.

6. The central vacuum cleaning system of claim 5, wherein the status indicator is a bi-color Light Emitting Diode (LED) that does at least one of illuminates a different color and flashes at a different frequency for a different signal.

7. The central vacuum cleaning system of claim 2, wherein the first signal relates to maintenance of the filter or the dust container, and the second signal relates to maintenance of the motor.

8. The central vacuum cleaning system of any one of claims 1 to 7, further comprising a second status indicator on the central vacuum power unit receiving the signals transmitted to the status indicator on the at least one of the handle portion of the flexible hose and the inlet of the air duct.

9. The central vacuum cleaning system of claim 2, wherein the control switch is used for the reset action.