SCR (Solid Control Rectifier) defective on McQuay WSC 087

[daniel s]

Dear colleagues,

I have problem on McQuay Water-cooled centrifugal chiller

Model number : WSC 087 MAU 49F/E3612/C3012.

The Chiller itself having problem during start (starter fault) at Line L3 - T3.
suspected The SCR (Solid Control rectifier) no #1 and no#4 defective causing unbalanced start. furthermore, excessive vibration on compressor during start and fail happened.

detail as written on the parts (SCR) is : Westcode uk BISCR1800
picture attached.

I need information about parts dimension (size in mm), since we can't dismantle them due to customer concern.
We've already get sourcing info about it, but some vendor gave us different type and size.

Hope that any engineer have experience on this would share to help me fix this kind of problem. should there any additional or other info which can be helpful, pls share..
Your kind attention is highly appreciated.

Regards, daniel