Contactor contacts uneven wear
Contactor contacts uneven wear
(OP)
Hi all,
I'm a recent graduate so I have a simple question. What should uneven wear/pitting on a contactor's contact surface face for wye delta starting tell me? It seems that only the upper portions have wear while the bottom 1/3 to 1/2 is unscathed. What should this tell me if anything at all. Is it normal? Thanks in advance for any response.
I'm a recent graduate so I have a simple question. What should uneven wear/pitting on a contactor's contact surface face for wye delta starting tell me? It seems that only the upper portions have wear while the bottom 1/3 to 1/2 is unscathed. What should this tell me if anything at all. Is it normal? Thanks in advance for any response.






RE: Contactor contacts uneven wear
1. Motors never ever have perfect current balance because of mechanical imperfections and supple voltage imperfections. For that matter, metal corrosion in s fuse clip burned up one of my customer's motors and after a rewind it would not come up to speed.
2. One contact will close first and open last because of mechanical imperfections. This will have the least wear.
3. When doing a wye-delta start, the delta contactor will have one contact more in phase depending on time delay.
Mike Cole, mc5w@earthlink.net
RE: Contactor contacts uneven wear