Customer stated DEL Table unit isn't heating as well as the other wells, will replace left two infinite switches. 10-09-18 Arrived, shut breaker off to unit. Replaced left two infinite switches, reassembled. Unit now tripped breaker immediately. Put old switches back in, breaker doesn't trip. Swapped around new switches, found new switches bad. Contacted factory to verify correct wiring and have correct part number. Will order new switches and return. 10-10-18 Arrived, installed two left side switches for wells. tested, okay.