McQuay MFU-C Product Manual page 5

GENERAL CHARACTERISTICS
AC2800B Electronic controller
Temperature range: 16-30° C.
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- 2-pipes/4-pipes model (through selecting J1 and J2).
Auxiliary electrical heater enable/disable (only for 2-pipes model, through selecting J3, default:
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open/disable, if enable, it output from terminal 5).
Cool/heat mode.
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- Fan speed can be set at high/medium/low.
Cold draft protection (under heat mode, the fan can run only when the water temperature is above 30°C ).
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Sensor failure alarm.
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LEDs show running state:
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1) The three blue LEDs show fan speed high/medium/low.
2) The dichromatic LED shows heat and cool mode: the red LED shows heat mode, the green LED
shows cool mode.
3) The red LED shows ON/OFF of the system.
4) The room sensor failure alarm: high speed LED blinks and shuts off all outputs.
The water sensor failure alarm: medium speed LED blinks and shuts off all outputs.
5) Mode conflict: the mode LED blinks and shuts off all outputs.
NOTES
1. Mode conflict: for 2-pipes model, when the system works on heat mode and the water temperature is
blow 25° C, or when the system works on cool mode an d the water temperature is above 25° C, the system
considers it fault as the mode conflict. At the same time, the system will shut off all outputs and the mode
LED will blink.
2. For 4-pipes model, the water sensor is fixed on the pipe of hot water.
CHILLED WATER FAN COILS – McQuay
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