Canatal M52 - Sequence of Operation

M52 Microprocessor User's Guide
M52UMCT Oct-03 6
Sequence of Operation
The following is an outline of the operation of the unit. Not all units have all options.
1. Unit powered
2. Canatal Banner appears and controller beeps three times.
3. Microprocessor initializes Co-Work and runs self check.
4. Random start timer activates
5. Restart delay counts down
Phase Loss (OPTION):
On loss or cross of a phase of supply power the unit will shut down or display Phase
Loss alarm. You must acknowledge the alarm and correct the phase before the unit will
restart
.
6. Blower starts (Blower runs continuously) when unit is in the ON position and when
Restart mode is set to Auto.
7. Warm-up period begins to allow time for steady signal from sensors. Temp/Hum
readings flash on screen during warm-up.
8. DX systems, crankcase heaters are energized when compressor is OFF through auxiliary
N/C contact on compressor contactor.
9. Air cooled DX units with flooded condenser Low Ambient Control (LAC) N/C
auxiliary contact on compressor contactor energizes receiver heaters.
Analogue and digital outputs for functions
Cooling 0-10 vdc and 1 or 2 triac outputs
Heating 0-10 vdc and 1, 2 and/or 3 triac outputs
Humidifying 0-10 vdc and 1 triac output
Dehumidifying 0-10 vdc and 1 or 2 triac outputs
DX Demand (Cooling)
Cycles on compressors in stages 1 to 8 depending on number of units connected together with Co-
Work as demand for cooling increases from 0 to 100%. The compressor will continue to run for a
minimum time of 1-5 minutes (default is 1 minute) to allow oil return to the compressor.
Demand for compressor:
• Compressor contactor and liquid line solenoid receives signal from microprocessor. Positive
Start timer (Pos. start delay) starts and bypasses LP switch for cold start-up. When HP switch
is closed the start circuit is complete and the compressor starts.
• N/C auxiliary contact on compressor contactor opens and de-energises receiver heaters.
(Flooded Condenser LAC)