HVAC Photos Chiller Control - Old McQuay Chiller Control Panel - Electro-Mechanical Controls
This panel is part of the controls for an older McQuay chiller. New chillers whether they be McQuay, Trane, York, or Carrier chillers still require these types of controls in them to make them work. This part of this electro-mechanical control panel consists of contactors and switches (both manual and automatic) for electro-mechanical control of this chiller. To the right is the main power which feeds the unit with three phase main power. This power is first fed into a manual disconnect switch so that power can be secured to the unit if maintenance or repair is necessary. from there, the power is split between three separate loads.
The first load the main power supplies is the compressors. Before the main three phase power arrives at the compressor contactors it goes through additional manual switches so the the compressor circuits can be isolated if necessary. The compressors have overload protection built into the compressors.
The second load to which main three phase power serves is the fan contactors. There are eight three phase fans for this chiller so there are eight separate contactors for each fan.The fans have overload protection built into them in the fan motors.
The final load which is fed from main power is the step-down transformer. This transformer provides single phase voltage to other electro-mechanical controls (not pictured) which control the contactors shown in this picture.
