High inrush current damaging relays

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High inrush current damaging relays

Post by om_tech_support_JT » Wed Aug 06, 2014 4:59 pm

Q: I have a 2RK6GN-AWU motor set up to be controlled with relays for CW/CCW operation, and the relay contacts are getting too hot and welding together. The relays handle 10A, and I'm measuring about 15A peak. Using a 3.5 mF capacitor which was included with my motor. Let me attempt to explain my wiring ~ if we look at the capacitor as ABCD where A and B prongs are on one side and C and D on the other, I have red wire to B, white wire to D, a 24VDC relay to A and another to C which connects single-phase 115VAC to A or C. Black wire is straight to GND.
-Omron relay: G2R-ISND-DC24S
-I measured about 2A RMS.

Can you help? I would prefer not to change out my relays since there are many machines in the field already. I would be interested in a quick fix if at all possible.

A: Your wiring is correct. We would recommend using the EPCR-1201-2 CR circuit for surge suppression. Please click on the link below to view the item:

http://catalog.orientalmotor.com/item/a ... epcr1201-2
EPCR1201-2 CR Circuit for surge suppression.png
EPCR1201-2 CR Circuit for surge suppression.png (45.14 KiB) Viewed 5125 times
This product is used to protect the contacts of the relay or switch used in the forward/reverse circuit section or the instantaneous stop circuit section of a motor. It will resolve your high inrush current issue. We have used this product to resolve similar issues in the past.

Here's an example of a wiring diagram that shows where to wire the ECPR1201-2 between a motor and a controller. You can reference this wiring diagram for your relays.
-the wiring diagram is between an ES01 controller + a 2RK6RGN-AW2U (slightly different speed control version) while using a double throw, double pole switch.
-please scroll down to see relevant information.
-The C0 and R0 in the wiring diagram is where the EPCR-1201-2 should be. You will need two for CW/CCW operation.
EPCR1201-2 wiring with ES series controller + motor.png
EPCR1201-2 wiring with ES series controller + motor.png (130.43 KiB) Viewed 5125 times

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