Mitsubishi Electric EHGT17D-YM9ED Service Manual page 56

9-6. Checking component parts' function
Water circulation pump (primary circuit)
Signal cable
3
M
1~
3
Power cable
<Recommended water flow rate range>
Heat pump unit
EHGT17D-YM9ED
Water circulation pump (sanitary circuit)
Immersion heater
Flow sensor
Flow signal V
5V DC
OCH722A
Part Name
BROWN
PWM input signal
BLUE
Signal ref.
BLACK
Feedback signal
BROWN
L
BLUE
N
GREEN/
YELLOW
Water flow rate range [L/min]
7.1-27.7
L N
M
1~
1
4
CN1A
Checkpoints
<Water circulation pump (primary circuit) characteristics>
80
70
60
50
40
30
20
10
0
0 5 10
Flow rate [L/min]
Brine Circulation Pump Characteristics
100
80
60
40
20
0
0 10
Flow rate [L/min]
Measure the resistance between the terminals with a tester.
(Winding temperate 20°C)
Terminal Normal (speed 2)
L-N 211 Ω
DHW circulation pump MUST be set to speed 2.
Measure the resistance between the terminals with a tester.
(Winding temperate 20°C)
Terminal Normal
A-B 19.2 Ω
To reset the immersion heater use a pin or similar to press the reset button lo-
cated on the top of the immersion boss.
See diagram on the left.
Flow signal
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.35V
0.0
0 20 40
Flow [l/min]
56
Speed 1
Speed 2
Speed 3
Speed 4
Speed 5
15 20 25
20 30 40
Abnormal
Open or Short
Abnormal
Open or Short
60 80 100
30