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Home > Industry Information > Installation, use and maintenance of thermal relays

Installation, use and maintenance of thermal relays


(1) When installing the wiring of the thermal relay, the dirt on the surface of the contact should be removed to avoid the circuit failure or the contact resistance is too large to affect the operating characteristics of the thermal relay.

(2) The thermal relay incoming terminal terminals are marked as l/L1, 3/L2, and 5/L3, and the corresponding outgoing terminal markings are 2/T1, 4/T2, and 6/T3.

(3) The thermal relay with the same rated current as the motor to be protected must be selected. If it is not met, the protection will be lost.

(4) In addition to the wiring screws, the thermal relays must not be screwed, otherwise the protection characteristics will change.

(5) When the thermal relay is installed and wired, the power must be turned off.

(6) When the thermal relay is installed with other electrical appliances, it should be installed under other electrical appliances to prevent its operating characteristics from being affected by the heat of other electrical appliances.

(7) The main circuit connecting wire of the thermal relay should not be too thick or too thin. If the connecting wire is too thin, the axial thermal conductivity is poor, the thermal relay may move in advance; conversely, the connecting wire is too thick, the axial heat conduction is fast, and the thermal relay may lag.

(8) When the motor start-up time is too long or the number of operations is too frequent, the thermal relay may malfunction or burn out the electrical appliance. Therefore, the thermal relay is generally not used for overload protection.

(9) If there is rust on the bimetal of the thermal relay, use a cotton cloth and rub the gasoline gently, and avoid sanding with sandpaper.

(10) When a short circuit accident occurs in the main circuit, check whether the heating element and the bimetal have been permanently deformed. If it has been deformed, it should be replaced.

(11) The thermal relays are adjusted to the automatic reset form at the time of shipment. If you want to adjust to manual reset, you can rewind the screw in the side hole of the thermal relay by about three or four turns.

(12) After the thermal relay trips. To start the motor again, the thermal relay must be reset before the thermal relay is cooled. Generally, the automatic reset takes 5 minutes, and the manual reset takes 2 minutes.

(13) The setting current of the thermal relay must be adjusted according to the rated current of the motor. When making adjustments, it is absolutely not allowed to bend the bimetal.

(14) In order to make the setting current of the thermal relay match the rated current of the load, the adjustment knob can be rotated to align the required current value with the white arrow, and there may be an error between the current value on the knob and the setting current value. In actual use, it should be deflected as appropriate. To adjust the current value between the two scales, turn the adjustment knob proportionally and adjust it properly during actual use.

Thermal Relay is used to protect AC three-phase asynchronous motor/electric motor against overload and open phase. Korlen electrical appliances produce  thermal relay switch in wholesale,being a good thermal overload relay suppliers from china. We also offers Manual Motor Startor , AC Contactor, led light, Circuit Breaker etc.

Thermal Relay, Latching Relay, Reed Relay, Polarized Relay
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