Conair CHS-810 manual Example, Relay Setting, Wiring Diagram

Example

The granulator is equipped with a current sensing relay to control a conveyor. A motor of 7.5 kW has a rated current of about 15 A.

When this star/delta is started, it pulls about 15 A/ i.e. about 9 A per phase.

C T1

Relay Setting:

Motor size 15 A/ = 8,7 A per phase

T1 – Start delay setting 0.1 second.

T2 – Reaction time setting 3.0 seconds.

A– Hysteresis 20 %.

B– Limit value 30 %.

C – Relay function N normal. A T2 B

•The current transformer size is 30/1A.

•The current transformer is connected to E2 (1 A).

•In a current transformer with a transformation ratio of 30/1, the limit value B should be set to 30 % or 9 A (30 A = 100 %).

•The current sensing relay detects the current consumption of the granulator motor and stops the conveyor, when the granulator motor exceeds 9 A for 3 seconds, to prevent further material from being fed into the hopper.

•The relay re-starts the conveyor automatically when the granulator motor consumption has fallen 20 % below 9 A, i.e. to 7 A without a time delay.

9 Wiring Diagram

W i r i n g D i a g r a m l 9 - 5