Probable cause
Action
7
Faulty Speed Board or
Merlin II
(if
fitted)
Remove board and jumper terminals C and T on the
controller. Note: When thermostat wires are connected
directly to C and T on the controller, the compressor will run
only at its slowest speed.
Speed Board
must not be
installed with
Merlin II
8
Compressor plug not connected
Disconnect the controller by removing the retaining screw.
Then ensure that the 3-pin plug is seated firmly on the pins of
the compressor.
9
Faulty compressor
(Highly unlikely)
Remove the controller as above, unplug from the compressor.
Check that ohm readings are the same across all terminals of
the compressor and there is no continuity to ground.
Do not
attempt to connect power directly to compressor.
10
Heat sink overheated
Allow components to cool down before attempting re-start.
11
Compressor too cold
If compressor is below freezing temperature, allow to warm
up before attempting re-start.
11:2
Compressor attempts to start, or starts then stops soon after
Probable cause
Action
1
Faulty or inadequate power
supply (Most likely)
Monitor the supply voltage at the power terminals on the
controller before, during, and after start attempts to ensure
that it does not fall below threshold levels. If it does, check
power supply, ground connections, and components for
integrity. Check for correct wire sizing. Charge batteries, if
necessary.
2
Faulty fan or pump relay or
unauthorized component
installed
Remove connectors from F and + terminals on controller and
attempt re-start. Maximum current draw on these terminals is
limited to 0.7 amps at 12v.
3
Quick Connect fittings not made Check that all refrigerant couplings are properly made.
11:3
System runs, box temperature too high
Probable cause
Action
1
Thermostat setting
Rotate mechanical thermostat knob clockwise to a higher
number, or adjust set point on Coastal MK3 model.
2
Speed setting
Check that the speed setting is the one recommended for the
installed evaporator and for its intended use, i.e. refrigerator
or freezer.
3
Thermostat type
If planning to convert an icebox into a freezer, or to a
spillover system, a freezer thermostat (blue housing) must be
used. Bin (B) and Horizontal (H) evaporators must be
controlled by a refrigerator thermostat in normal applications.
