Input States - Parker Airtek Magnum MSC4000 User Manual

Input States

Low Refrig Switch Sense Input
• ON indicates that the pressure at the low side of the compressor is above the mechanical
setting of the low pressure switch.
• Indicator is off when the switch opens due to low refrigerant pressure.
• The switch resets automatically when the pressure rises above the switch threshold.
High Refrig Switch Sense Input
• Wired in series with the low pressure switch.
• ON indicates that the pressure at the high side of the compressor is below the mechanical setting of the high
pressure switch and the pressure at the low side of the compressor is above the mechanical setting of the low
pressure switch.
• OFF Indicates that either the low pressure switch or high pressure switch is open.
• The high pressure switch must be manually reset at the switch.
Compressor #1 through #4 Fault Sense Input
• Wired in series with the low and high pressure switches,
corresponding compressor's PLC output relay, oil pressure switch, and thermal overload.
• Direct drive compressors – The fault relay is located on the starter over-load for the corresponding compressor
and must be reset at the overload module.
• Variable Speed compressors – Alarm relay is located on the variable speed drive for the corresponding com-
pressor and must be reset at the drives front panel.
Compressor #1 through #4 Low Oil Pressure Sense Inputs
• Wired in series with low and high pressure switches, and corresponding compressors PLC output relay.
• On indicates that there is adequate oil pressure for the corresponding compressor after an initial 120s delay.
Compressor #1 through #4 Oil Level Monitor Sense Inputs
• ON indicates that there is adequate oil level for the corresponding compressor.
Emergency Stop Switch OK
• Normally ON. OFF indicates the normally closed emergency stop switch has been pressed.
Control power Fuse 'A' & 'B'
• Normally ON. OFF indicates the corresponding fuse has opened.
Drain Level Switch #1 & #2
• ON indicates the corresponding drains float switch is closed as a result of the demand drain reservoir being full.
Remote Switches
• Used for remotely controlling the dryer using external switches or external PLC relay outputs.
Refer to Remote PLC Operation section (page 60) for details.
MSC4000 - MSC15000 USER MANUAL
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