THERMEx THW100, Руководство по эксплуатации продукта

Страница: 31 / 58

Heat Pump Manual
31
OPERATION
The maximum operational water temperature is 60°C – the water temperature setting
should not be set above this. The unit can be constructed to operate at up to 70°C but
this MUST be specified at the time of order. Operating a standard unit above 60°C will
void the warranty on the compressor.
CONTROL
Operational logic is as follows
Start-up
– Pump enable ON, 10 second delay and then flow switch should have closed
indicating that pump is running OK.
After compressor hold time and set point minus hysteresis COMPRESSOR ON
If on the larger units
– 80 and 100kW there are two compressors the second compressor will
start when the temperature is at set point minus 4 degrees
If a compressor should fail then the unit will keep running
The unit has solenoid valves that are used for de-icing control however they open up when
the compressor starts for 10 seconds to prevent pressure drops and nuisance trips due to low
suction pressure.
If water temperature reaches set point them compressor OFF. Unit then waits for both the
hysteresis and compressor hold time again and then starts compressor.
These is a setting in the controller
– “Last off Hysteresis” – normally set at 0.5C – in dual
compressor units the controller will cut the second compressor off 0.5C before set point to
stop both compressor from crashing off when set point is reached.
Temperature Control – Set Point
Compressors will turn compressors off when the set point is breached. Compressors will be
turned on again at temperature minus hysteresis. Default temperature setting is 60 degrees
and the hysteresis is 2 degrees. So at 60 degrees water temperature in the storage tank
compressor off and compressor on when again when temperature at 58 degrees AND
compressor rest time elapsed.
If there are slave units installed then the master controller will progressively bring on the slave
units when the as the temperature continues to drop and will turn them off when the set point
is reached.
Temperature Control – Max and Min Set Point
This prevents casual operator from setting supply temperatures too high or too low
High Pressure Control
The unit has a mechanical high pressure safety switch that activates when the pressure in
the discharge side of the system reaches 300 psi.
Temperature Offset Co.
This setting in the controller sets a limit between the storage tank temperature and the water
supply through the heat pump. It is designed as a safety setting
– the heat pump is supplying
water more than 15C higher than the storage tank temperature then the is a problem in the
system
– in this case most likely a flow fault