JPS59128986A - Starting equipment for air conditioner - Google Patents

Abstract

PURPOSE:To aim at improvements in reliability, by making a compressor so as not to start operation unless a crankcase has been energized with a continuous rating current for a specified period of time, and after the elapse of the specified time, enabling the compressor to restart even to power failure in a main power source within a set time after restoration. CONSTITUTION:Two phases of a three-phase power source 20 and a timer device 28 are connected together, while a crankcase heater 24 is energized with a continuous rating current by a first setting time T1 and a temperature of oil is raised up. Therefore, oil foaming comes to nothing, preventing a valve crack in a compressor 23, wear in a sliding part, seizure or binding in a shaft, etc., thus reliability is improved. In addition, since lock operation in the compressor 23 is eliminated, no overcurrent flows there so that oil degradation due to an abnormal rise in oil temperature can be prevented as well. Moreover, since a second setting time T2 is set up there, reduction in a waiting period of time due to power interruption after the elapse of the first setting time is well promoted, and likewise, in spite of being still high in the oil temperature after the power interruption, the need to energize the crankcase heater 24 again for the first setting time T1 becomes unnecessitated, thus the promotion of energy-saving is attainable.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an air conditioner having a refrigeration cycle in which a crankcase heater is wrapped around a compressor.

Structure of a conventional example and its problems FIG. 1 shows a conventional starting device for an air conditioner. In the figure, 1 is a three-phase power supply, which is connected to a compressor 4 via a main power switch 2 and a relay contact 3. A crankcase heater 6 is also connected via the b contact 5 of the relay. Reference numeral 7 is an operating power source, which is connected to an operating switch 8 and a relay coil 9 in sequence.

First, the operation of the above conventional example will be explained. When the main power switch 2 is turned on and then the operation switch 8 is turned on, the relay coil 9 is energized, the relay contact 3 becomes conductive, the compressor 4 starts rotating, and the air conditioner starts operating. However, in the conventional example 11, when the operation switch 8 is turned on after a short time after the main power switch 2 is turned on, the compressor 4 is heated without increasing the oil temperature in the compressor by the crankcase heater 6. As the refrigerant starts immediately, the oil containing the refrigerant accumulated inside the compressor causes oil forming, and the oil is discharged from the discharge pipe along with the liquid refrigerant, entering the refrigeration system and reducing the heat exchange capacity. This may cause valve cracking due to cavitation, accelerate wear of the sliding parts inside the compressor due to a decrease in the amount of remaining oil in the compressor, cause burnout of the shaft, or cause heat from wear. It had drawbacks such as deteriorating the performance of the coconut oil.

The present invention based on the Q-rule is intended to eliminate the drawbacks of the above-mentioned conventional examples, and aims to improve the quality at the time of starting up the compressor and eliminate the inconvenience in actual use.

Aspects of the Invention The present invention includes a crankcase heater wrapped around the bottom of the compressor and a timer device connected to the operating circuit side in the middle of the circuit connected from the power source to the compressor via the main power switch and relay contacts. This timer device prevents the compressor from starting until the crankcase heater has been energized for a predetermined period of time, and after the predetermined period of time has elapsed, it can be started after power is restored in the event of a main power outage within a certain period of time. It is intended to do so.

An embodiment of the present invention will be described based on FIGS. 2 to 4. In Fig. 2, 20 is a three-phase power supply, 21 is a main power switch, 22 is a relay contact, 23 is a compressor, 24 is a crankcase heater wrapped below the compressor case, and b
It is connected to two phases of a three-phase power supply 20 via a contact 25 . 26 is the operating power supply of the operating side circuit, 27 is the operating side switch,
Reference numeral 28 denotes an electronic or mechanical timer device, which is connected to two phases on the three-phase power supply side. Reference numeral 29 is a relay coil of the relay contact 22, with one end connected to the timer device 28 and the other end connected to the operating power source 26.

Reference numeral 30 denotes a backup power source or a power storage device for driving the timer device 28 when the power supply to the timer device 28 is cut off.

Next, the operation of the above embodiment will be explained. In FIG. 2, when the main power switch 21 is turned on, the timer device 28 starts counting the first set time T, and at the same time, electricity is applied to the crankcase heater 24 via the B contact 25, and the bottom of the compressor 23 starts to be heated. . Until the first set time T is counted, the relay coil 29 is not energized even if the operating switch 27 is turned on, so the relay contact 22 is not operated and the compressor 23 is not started. When the counting of the first set time T1 is completed, the timer device 28 enters a standby state to count the second set time T2, and at the same time, when the operation side switch 27 is turned on, the timer device 28 becomes in a state where the relay coil 29 can be energized. If the power supply is stopped due to a power outage after the first set time TI has elapsed, the second
Start counting the set time T2. At the same time, the backup power source 30 or the like drives the timer device 28 to activate the timer device 28. During this power cutoff, the timer device 28 is maintained in a state where the relay coil 29 can be energized, and when the power supply is restored, the timer device 28 is activated from the three-phase power source 20 side. The above operation is performed during the second set time T2, but T2
When , the first set time T! Start counting T.
The relay coil 29 is not energized until 1 elapses. The above is until the compressor 23 starts up,
After the compressor 23 is started, if the power supply is cut off due to a power outage, etc., a second set time T2 is counted, and if the power supply is restored during that time, the relay coil 29 is energized and the compressor is started. After the second set time T2 has elapsed, it starts counting the first set time TI, and is not activated until T1 has elapsed.

In this embodiment, since the compressor 23 does not start until the first set time T1 elapses, the temperature of the oil in the crankcase heater rises during the first set time TI, and the liquid refrigerant is vaporized and separated from the oil. It has the advantage of preventing oil foaming. In addition, if there is a power interruption such as a power outage, a second set time T2 is set, and if it is within T2, it can be started after the power is restored, or if it is running, the oil temperature is high to a certain extent, so there is no possibility of the refrigerant penetrating into the oil. Since it can be restarted, during the first set time TlO after the power is turned off,
It is possible to operate the equipment without waiting for it to start up, and it can be used without wasting time unnecessarily.
This eliminates inconvenience in use while ensuring the quality of the equipment even during maintenance.

As shown in FIG. 3, when the timer device 31 is connected to three phases of a three-phase power source and driven, it is used together with a single-phase operation preventer 32 that prevents single-phase operation of the device to prevent abnormal operation of the device. This has the advantage of making it possible.

Figure 4 is a time chart, ON while operating.
, is shown as OFF while not operating.

In the embodiment of the present invention, a three-phase power supply has been described, but a single-phase power supply may be used, and in this case, the second embodiment is unnecessary. Further, although the operating power source is shown as a separate power source, it may be the same as the optical power source or may be a DC power source, as long as it is a power source for driving the operating circuit.

Effects of the Invention 1 The present invention has the above-described configuration, and the following effects can be obtained.

(1) Since the crankcase heater is energized at the first set time T1 to raise the oil temperature, oil foaming is eliminated and compressor valve cracking, sliding part wear, shaft seizure, etc. can be prevented.

(2) Seizing of the shaft, etc. is eliminated, and the compressor is no longer locked, so no overcurrent flows, and therefore the oil temperature does not become abnormally high and cause oil deterioration.

(3) Due to the effects of (1) and (2) above, the life of the equipment is extended and its reliability is improved.

(4) Since the second set time T2 is provided, the waiting time due to power cutoff after the first set time has elapsed can be shortened, eliminating inconvenience in use.

(5) Since the second set time T2 is provided, the crankcase heater is not energized again during the first set time TI after the power is cut off, even though the oil temperature is high, resulting in energy savings. have.

(6) Since it has a single-phase operation preventer, it is possible to prevent overheating due to single-phase operation of the compressor, eliminating abnormal operation of the equipment.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a conventional air conditioner starting device, FIG. 2 is a circuit block diagram of an air conditioner starting device of the present invention, and FIG.
The figure is a circuit block diagram of another embodiment of the present invention, and FIG. 4 is a time chart of the same. ■...Three-phase power supply, 2...Main power switch, 3...Relay contact, 4...Compressor, 5...B contact, 6...
Crankcase heater, 7... Operating power supply, 8... Operating switch, 9... Relay coil, 20... Three-phase power supply, 21... Main power switch, 22... Relay contact, 2
3...Compressor, 24...Crankcase heater, 25
... B contact, 26 ... Operation power supply, 27 ... Operation side switch, 28° 31 ... Timer device, 29 ... Relay coil, 30 ... Backup power supply, 32 ...
・Single-phase operation preventer. Figure 1 Figure 2

Claims (2)

[Claims] (1) A crankcase heater is wrapped around the bottom of the compressor, and the operation circuit is configured to start the compression after the crankcase heater is energized for a predetermined set time, and after the set time elapses, the power is shut off within the specified time. On the other hand, a starting device for an air conditioner is characterized in that a timer device is connected to the device to restart the air conditioner after a predetermined period of time has elapsed since the power was cut off. (2) The starting device for an air conditioner according to claim (1), which is provided with a single-phase operation preventer for preventing single-phase operation of the m unit.