CN201215890Y

CN201215890Y - Anti-burning automatic protection device for low-voltage distribution transformer

Info

Publication number: CN201215890Y
Application number: CNU2008200020024U
Authority: CN
Inventors: 刘振安
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-01-01
Filing date: 2008-01-01
Publication date: 2009-04-01
Anticipated expiration: 2018-01-01

Abstract

The utility model discloses an anti-fire automatic protector of a low-voltage distribution transformer, which is characterized in that a temperature sensor is inserted into a top of the transformer and extends deep into a temperature measuring hole whose inner is sealed, a wire is correspondingly connected with an automatic temperature control device, the connecting terminal of an automatic control switch is connected in series in a connecting closed circuit between solenoids of a phase and amplitude discrimination leakage relay and an AC contactor, the temperature is set within the critical temperature value of the transformer, when the temperature of the transformer reach or approach the critical temperature value due to overloading the winding temperature of the transformer, the alarming indication can be automatically started and the power supply on the solenoid of the AC contactor can be cut by an automatic temperature controller, thereby the AC contactor is enforced to trip and the loading on the low-voltage side is cut off, when the temperature is lower than the critical temperature value, the power supply is automatically recovered, thereby the transformer can be prevented to be burnt out due to the inner temperature is over high, the protector has no interference to the original functions, the functions are respectively played, and the utility model has the advantages of labor saving, low cost, temperature measurement is accurate and directly viewed, and the use is reliable and safe.

Description

The anti-automatic safety device that burns of low voltage distribution transformer

Technical field:

The utility model relates to a kind of protective device of low voltage distribution transformer, the anti-automatically protective device that burns of especially a kind of transformer thereby heating former because of overload operation etc.

Background technology

At present, various protectors to low voltage distribution transformer (abbreviation transformer) have various primary cut-outs in the high-pressure side, lightning arrester etc., low-pressure side has various fuses, A.C. contactor, phase-detecting amplitude-detecting leak relay etc., although safeguard measure like this is arranged, but because the transformation capacitance grade is various, the various protection facilities that match with it are difficult to conform to, the capacity of joining is little to be burnt out easily, often all take configuration bigger than normal, so far usually because of overload operation and line fault short circuit, cause the anxious huge intensification of winding current overcurrent heating and burn transformer, cause its economic loss; Put near the high position of winding temperature rise at the top cover of original transformer the one sealing circular hole that plug in thermometer arranged is set, in order to measure the temperature of its inner tip, but the user is very little, observe not science and unrealistic of the too high and way of burning of monitoring prevention transformer temperature with this mode, making it be arranged on the transformer top cover becomes ornaments in order to the thermometer hole of observing its internal temperature.

The utility model content:

The purpose of the utility model is very the deficiency that above-mentioned prior art is existed and provides a kind of low voltage distribution transformer the anti-automatic safety device that burns.It comprises compositions such as the temperature sensor in the thermometer hole, automatic temperature control device on existing distribution transformer and high and low voltage electric distribution equipment and the reeve transformer top cover, and is of a great variety because of temperature-sensing element, is that example is illustrated with the temperature sensor only just.

The utility model is achieved in that temperature sensor inserts in the transformer top cover thermometer hole, with the corresponding connection of lead with automatic temperature control device, automatic control switch in order to automatic control circuit on the automatic temperature control device is serially connected in the circuit of phase-detecting amplitude-detecting leak relay and A.C. contactor two line bag closures, makes the line bag on the A.C. contactor be subjected to dual control.The maximum temperature of automatic temperature control device is limited to the critical temperature value that transformer can bear, so be formed on the transformer temperature rise normally at present, automatic control switch is in closure state, but the phase-detecting amplitude-detecting leak relay still keeps original would trip function during Leaked Current of Line to Ground.When causing the anxious huge intensification of overcurrent winding when transformer overload or line fault short circuit, being inserted in temperature sensor in the transformer top cover hole will conduct its internal temperature signal to automatic temperature control device at any time and give digital the demonstration, when temperature is raised near critical temperature, automatic temperature control device will start AIS, and warning operator is adjusted load immediately to guarantee the normal operation of transformer.If under unattended situation; the transformer internal temperature will continue to raise; thermostat will send driving command when rising to critical temperature value; order about the automatic control switch action; thereby cut off the closed circuit between phase-detecting amplitude-detecting leak relay and the A.C. contactor line bag; until forcing the A.C. contactor tripping operation to disconnect the load of low-pressure side; make transformer be in Light Condition; the inner winding temperature of transformer this moment will descend gradually; when dropping to the subcritical temperature value; automatic temperature control device will send driving command; make the closed power supply of connecting A.C. contactor line bag of automatic control switch, make the A.C. contactor adhesive, make transformer recover normal powered operation state; thoroughly exempt the passive situation that transformer is burnt because of overload, achieve a kind of anti-automatically defencive function that burns of addition in low-voltage power supply system.

The utility model is the automatic protection setting of adopting near the true temperature of winding according to inside, transformer top; have the ambient temperature of not being subjected to influences for this reason, is that performance is very stable accurately and effectively with giving the anti-automatic safety device that burns of low pressure oil-immersed distributing transformer.

Of a great variety because of temperature-sensing element, only to be described at this with temperature sensor, in the described insertion transformer thermometer hole is temperature sensor, also can insert the temperature-sensing element of other kind certainly.

Advantage of the present utility model just is: only need the said equipment device at certain position and connect can realize the anti-automatic protection functions that burns of transformer in corresponding circuit; have with low costly, device connects simple, and thermometric is accurate and visual; use characteristics such as reliable and secure, saving guard.

Description of drawings:

The utility model is described in further detail below in conjunction with accompanying drawing.

Fig. 1 is a circuit theory connection diagram of the present utility model.

(1), temperature sensor among Fig. 1, (2), the transformer thermometer hole, (3), transformer, (4) automatic temperature control device, (5), alarm, (6), signal lamp, (7), automatic control switch, (8). (9), switch terminal, (10) phase-detecting amplitude-detecting leak relay, (11). (12), phase-detecting amplitude-detecting leak relay line bag terminals, (13). (14), A.C. contactor line bag terminals, (15), A.C. contactor.

Embodiment:

In Fig. 1; temperature sensor (1) is inserted transformer (3) top cover to be goed deep in its inner thermometer hole (2); and be connected with automatic temperature control device (4) with lead; automatic control switch (7) stretches to two terminals (8) of outside; (9) be connected with A.C. contactor line bag terminals (14) with phase-detecting amplitude-detecting leak relay line bag terminals (12) respectively; phase-detecting amplitude-detecting leak relay line bag terminals (11) are connected with A.C. contactor line bag terminals (13); so with its whole energized; all protective devices will enter full-automatic protection running status; when circuit makes the inner heating in winding of transformer (3) rise near critical temperature because of excess load or phase fault overcurrent; the interior temperature sensor (1) of thermometer hole (2) that inserts its deep inside sends temperature signal to automatic temperature control device (4); automatic temperature control device will excite alarm (5) and signal lamp (6) to be warned simultaneously; the prompting operator on duty in time adjusts supply load, to guarantee the normal operation of transformer.Under unattended situation; the transformer internal temperature will continue to raise; automatic temperature control device when rising to critical temperature (4) will start driving command; make the closed circuit between automatic control switch (7) disconnection phase-detecting amplitude-detecting leak relay and the A.C. contactor line bag; force A.C. contactor (15) tripping operation and the load of cutoff low side; make transformer (3) be in Light Condition; this moment is non-loaded because of transformer; inner winding temperature will descend gradually; when being brought down below critical temperature value; automatic temperature control device will excite driving command; drive the circuit between automatic control switch (7) connection phase demodulation amplitude discrimination leakance electrical relay and the A.C. contactor line bag; make the A.C. contactor adhesive, transformer (3) recovers normal powered operation state, realizes its anti-effective efficiency of protection automatically that burns.

Claims

1. a low voltage distribution transformer prevents burning automatic safety device; it comprises transformer (3); transformer thermometer hole (2); A.C. contactor (15); temperature sensor (1); automatic temperature control device (4); alarm (5); signal lamp (6); automatic control switch (7); the phase-detecting amplitude-detecting leak device (10) that continues; A.C. contactor devices such as (15) combines with the lead connection; it is characterized in that: the thermometer hole (2) on transformer (3) inserts a temperature sensor (1), and is connected with automatic temperature control device (4) with lead, with automatic control switch (7); the line bag of phase-detecting amplitude-detecting leak relay and the line bag of A.C. contactor are serially connected in it in closed circuit with lead.

2. the anti-automatic safety device that burns of low voltage distribution transformer according to claim 1 is characterized in that: be set with critical temperature value on automatic temperature control device (4).