McQuay PHH079

[Khaled Adel]

Hi .. it's eng.Khaled from Egypt

I've already bought a chiller from McQuay International and its model is PHH079 from 1988 and now there's a problem in it, when it starts up with Star connection it works normally but when it converts the electrical signal to Delta connection it stops !!!! so may be there's a problem in contactors or another thing ?!!!

I need just a technical support to how deal with this problem ?! .. please inform me with solution.

thanks

[ptsac]

Hi Khaled,
Does the motor actually run in delta before tripping or does it not go into delta? If it goes into delta it should make some auxiliary contact to prove transition. These contacts will be on the delta contactor. What type of control panel do you have and what fault is indicated?