Micro-Air, Inc. Page 20 EasyTouch Operations Manual
Rev 3.0 4/3/17
1. If the low pressure switch is open while the compressor is off, the most likely cause is loss of
refrigerant charge in the system due to a leak.
2. If the low pressure switch is open while the compressor is operating in COOL mode, the most
likely causes are low refrigerant charge or cold seawater.
3. If the low pressure switch is open while the compressor is operating in HEAT mode, the most
likely causes are low refrigerant charge or cold inside air temperature. Setting the fan speed to
manual low can sometimes remedy low pressure faults in HEAT mode.
10.5 Low AC Fault (DX & FAMU DX only, no lockout)
Main Screen Display: “FAULT LOW AC”
FAMU Screen Display: “FAULT LOW AC”
Status Screen Display: “FAULT LOW AC”
Fault History Display: “LOW AC”
The Low AC Fault occurs whenever the AC line voltage is below the Low-Voltage Monitor parameter
setting during compressor operation for at least 5 minutes, or whenever it is below just before
compressor start-up. By default, the Low-Voltage monitor is not enabled. See section 12.3.3 for
more information on how to enable and set the voltage threshold for the Low-Voltage Monitor.
10.6 Pump Sentry Fault (DX & FAMU DX only, contributes to lockout count)
Main Screen Display: “FAULT PUMP”
FAMU Screen Display: “FAULT PUMP SENTRY”
Status Screen Display: “FAULT PUMP SENTRY”
Fault History Display: “PUMP SNTRY”
The Pump Sentry Fault occurs whenever the Service sensor temperature exceeds the Pump Sentry
parameter setting during compressor operation, or if it drops below 45°F/7°C (if Electric Heat is not
enabled; see section 12.1.14). Refer to section 6.3 for more information on how to install the optional
Service sensor, and section 12.3.5 for more information on how to enable and set the temperature
threshold for the Pump Sentry.
10.7 Overcurrent Fault (DX & FAMU DX only, contributes to lockout count)
Main Screen Display: “FAULT OVRCURR”
FAMU Screen Display: “FAULT OVERCURRENT”
Status Screen Display: “FAULT OVERCURRENT”
Fault History Display: “OVERCURR”
The Overcurrent Fault occurs whenever the system’s total AC current load exceeds the Current Limit
parameter setting for at least 30 seconds (sustained) or at any time prior to compressor startup while
the control is turned on. This fault protects the control board electronics, wiring, and compressor for
possible further damage.
The causes of overcurrent vary. Check the compressor and other AC loads for proper operation.
Also refer to the possible causes listed under the High Pressure Fault (section 10.3).
10.8 Lost AC Fault (DX & FAMU DX Only, no lockout)
Main Screen Display: “FAULT LOST AC”
FAMU Screen Display: “FAULT LOST AC”
Status Screen Display: “FAULT LOST AC”
Fault History Display: “LOST AC”
The Lost AC Fault occurs whenever the EasyTouch detects that the AC line voltage has been lost
during compressor operation (i.e. a brownout condition). Brownout conditions can cause
compressors to stall very quickly (<50ms), so this detection protects the compressor by shutting down
the compressor relay output and waiting for the normal fault recovery delay before attempting a
compressor restart.
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