Check For Proper Circulating Water Flow Rate; Notes On Temperature Adjustment Function; Connecting The Pump-Interlock Wire; Notes On Connecting The Pump-Interlock Wire - Mitsubishi Electric CAHV-P500YA-HPB Service Handbook

[ VIII Test Run Mode ]

(10) Check for proper circulating water flow rate.

Measure the circulating water flow rate, if possible. If it is not, check that the temperature difference between the outlet and
inlet temperatures is between 3 and 5 ºC. A temperature difference of 6ºC or more indicates not enough water flow. Check
for air pockets in the pipe, and make sure that the pump has the appropriate capacity for the circuit.
(11) Check that the unit is operating properly according to the temperature adjustment function.
When a pull-down operation is completed, check that the hot water temperature adjustment function will come on and that the
unit will automatically go on and off. Make sure the ON/OFF cycle (beginning of an operation until the next) is at least 10 min-
utes. (The unit features an anti-short-cycling protection.)

Notes on temperature adjustment function

The water temperature can be controlled based on the inlet or the outlet temperature sensor reading. Select one to use. Refer
to "VII [1]1.Factory Switch Settings (Dip switch settings table) and "(1)Setting procedures"(page 67) for how to select the water
temperature control method and how to set the water temperature.
Do not disconnect the power wire to the compressor in an attempt to keep the compressor from going into operation
during test run. (If it is done, the control board will not sense that the compressor is stopped, and the water temperature
will not be controlled properly and the unit may come to an abnormal stop.)
(12) Connect the pump-interlock wire to the appropriate contacts.

1) Connecting the pump-interlock wire

Connect the pump-interlock wire to the pump-interlock circuit (Terminal block
circuit is complete.

2) Notes on connecting the pump-interlock wire

Connect an NO relay (solenoid switch) for the pump.
This circuit is a low-voltage circuit. Keep the pump-interlock wire at least 5 cm away from any wire that carries a voltage of
100 V or above to avoid damage to the circuit board.
52P
51P
M
3
MP
(13) Checking the rotation direction of the pump
Check that the circulating water pump is rotating in the correct direction. If the pump is rotating in the wrong direction,
disconnect the pump wiring from the solenoid switch, and reconnect them so that the pump will rotate in the correct direction.
HWE10060
F
52P
51P
PL pump fault
Recommended pump circuit
and
11
Control box on the unit
Control board on the unit
71
3
70
1
- 98 -
). The unit will not operate unless this
12
11
52P
12
GB