FORM 150.26-EG1 (116)
JOHNSON CONTROLS
7
Equipment Overview (Cont'd)
POWER AND CONTROL PANELS
All controls and motor starting equipment necessary for unit operation shall be factory
wired and function tested. The panel enclosures shall be designed to NEMA 1 (IP 32) and
manufactured from powder-painted galvanized steel.
The Power and Control Panel shall be divided into a power section for each electrical
system, a common input section and a control section.
Each power panel shall contain:
• Compressor starting contactors
• Control-circuit serving compressor capacity control
• Compressor
• Contactor coils
• Compressor motor overloads
The compressor motor overloads contain current transformers which sense each phase,
as an input to the microprocessor, to protect the compressor motors from damage due to:
• Low input current
• High input current
• Unbalanced current
• Single phasing
• Phase reversal
• Compressor locked rotor
The common input section shall contain:
• Control supply transformer providing 115V
• Customer relay board
• Control circuit switch disconnect/emergency stop device
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