Considerations for selecting time relays

The selection of time relay is mainly a matter of delay mode and parameter coordination. The following aspects should be considered when selecting.
(1) Selection of delay mode. There are two types of time relays: power-on delay or power-off delay, which should be selected according to the requirements of the control circuit. The reset time after action is longer than the inherent action time to avoid malfunction or even no delay. This is especially important in repeated delay circuits and frequent operations.
(2) Type selection. For occasions where the delay accuracy is not high, lower-priced electromagnetic or air damping time relays are generally used; conversely, for occasions where delay accuracy is high, electronic time relays can be used.
(3) Coil voltage selection. The voltage of the time relay attraction coil is selected according to the control circuit voltage.
(4) Selection of power supply parameter changes. In situations where the power supply voltage fluctuates greatly, it is better to use air-damped or electric time relays than transistor types. However, in situations where the power supply frequency fluctuates greatly, it is not suitable to use electric time relays. In places where the temperature changes greatly, it is not suitable to use air-damped time relays. Damped time relay.