Common fault handling methods for intermediate relays
Intermediate relay is a kind of control relay. Generally used for auxiliary purposes, that is, when the control circuit requires a large number of contacts and a large capacity, the number of control loops can be increased or the signal can be amplified through the intermediate relay. When working, when the voltage of the coil reaches the specified value, the intermediate relay will act.
Since the structure of the intermediate relay is basically the same as that of the contactor, the common faults, diagnosis and countermeasures of the contact part and the electromagnetic system can refer to the relevant part of the contactor. It only needs to be pointed out that the contacts of the intermediate relay are prone to false connection faults. This fault often occurs during the working period of the electrical control. It does not necessarily occur frequently or fixedly, so it is difficult to catch and make the fault difficult to judge. But occasionally, it may cause major accidents. The reason for this kind of failure is due to the change of the contact resistance of the control circuit, which makes the actual voltage at both ends of the electromagnetic electric appliance coil lower than 85% of the rated voltage, so that the iron core cannot be pulled in and the circuit is out of control.
The best way to eliminate the fault is:
(1) Try to avoid using a low voltage of 12V and below as the control voltage, because in this low-voltage circuit, the contact failure is most likely to occur.
(2) When the control circuit uses 24V as the control voltage, parallel contacts should be used to improve its working reliability.
(3) When the control loop must use low voltage control, it is better to use 48V.
(4) It is better to use 110V and above voltage as the rated control voltage for the control loop, which can effectively prevent the phenomenon of virtual contact of the contacts.
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