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Only training and service purposes.
1.3 Electric Heater
*1 : When electric heater is working, ‘Electric Heater Operating’ is
displayed at control panel
*2 : For single-phase model : Measure electric voltage at port 3 (Live) and port 4
(Neutral) of Terminal Block 3 with voltage meter. The measured value should be
220-240 V~ . To identify the location of Terminal Block 3, please refer circuit
diagram of unit at ‘Installation Manual’ or backside of front cover of the unit.
*2 : For three-phase model : Measure electric voltage at two port of
3 (R), 4 (S), and 5 (T) of Terminal Block 3 with voltage meter. The
measured value should be 220-240 V~ or 380-415 V~ . To identify the
location of Terminal Block 3, please refer circuit diagram of unit at
‘Installation Manual’ or backside of front cover of the unit.
*3 : For single-phase model : Find cover of thermodisk which is located
beside air vent. Air vent is on the top of the electric heater tank. Uncover
the cover by unscrewing bolts. Find two copper leads located both left and
right side of the thermodisk core. Check resistance of both leads. The
measured resistance should be 0 ohm. After then, check if voltage is
transmitted to the thermodisk correctly. Measure electric voltage between
one of the lead (Live) of the thermodisk and port 3 (Neutral) of ELB (A).
The measured value should be 220-240 V~ .
*3 : For three-phase model : Find cover of thermodisk which is located
side of electric heater tank.Uncover the cover by unscrewing bolts. Find
two copper leads located both left and right side of two thermodisk core.
Check resistance of both leads of each thermodisks. The measured
resistance should be 0 ohm.
*4 : For single-phase model : Resistance between port 1 and port 2 should
be 0 ohm. Also, port 3 and port 4 should be 0 ohm, too. Finally, measure
electric voltage at port 2 (Live) and port 4 (Neutral) with voltage meter. The
measured value should be 220-240 V~ .
*4 : For three-phase model : Resistance between port 1-to-port 2, port 3-to-port
4, and port 5-to-port 6 of MCCB (A) should be 0 ohm. Port number and location
of MCCB (A) can be found circuit diagram of the unit(back side of front cover).
*5 : For single-phase model : At Relay Contactor (A), measure electric
voltage at port 2 (Live) and port 6 (Neutral) with voltage meter. The
measured value should be 220-240 V~ . Also, at Relay Contactor (B),
measure electric voltage at port 2 (Live) and port 6 (Neutral) with voltage
meter. The measured value should be 220-240 V~ .
*5 : For three-phase model : At Magnet Contact (C) or Magnet Contact (B),
resistance between port L1-to-port T1, port L2-to-port T2, and port L3-to-
port T3 should be 0 ohm.
Start
A
YES
YES
NO
Electric heater
working time
is not enough
YES
NO
B
Electric power
is not supplied
NO
C
YES
Thermodisk is
not correctly
working
NO
D
NO
E
YES
NO
YES
Relay
contactor
is not working
correctly
Electric heater
is not normal
F
Electric heater is
working
External electric
power supply OK?
Thermodisk
OK?
ELB or MCCB OK?
Relay Contactor
OK?
More than 5 minutes
elapsed since electric
heater working
*1
*2
*3
*4
*5
ELB (or MCCB) cuts off
Power or ELB
(or MCCB) trouble
• Wait for 5 minutes to heat water inside electric heater tank. If capacity of electric heater is 6kW, at least 2
centigrade will be increased.
• For single-phase model : Check if external electricity power supply is breakout. If not, check wiring between
external electricity power supply and port 3 and port 4 of Terminal Block 3. You can identify the location of Terminal
Block 3 at the circuit diagram of unit.
• For three-phase model : Check if external electricity power supply is breakout. If not, check wiring between external
electricity power supply and port 3, port 4, and port 5 of Terminal Block 3. You can identify the location of Terminal
Block 3 at the circuit diagram of unit.
• Thermodisk is mechanically defected. In this case, contact official After Service Center and replace the thermodisk.
• Check the insulation resistance of Electric Heater.
• If the insulation resistance has improper, remove the cause of the problem and then reset the ELB (or MCCB).
• Replace the ELB (or MCCB) when the insulation resistance is suitable.
• Relay contactor is is mechanically defected. In this case, contact official After Service Center and replace the relay contactor.
• Heating coil of electric heater can be damaged or wiring inside the electric heater is problem. Before replacing the electric heater, in
this case, contact official After Service Center and do diagnosis about electric heater and related parts including the capacity of
external electric power source. If the reason of malfunction is clearly proved as the defect of the electric heater itself, then replace it
with new one.
A
B
C
D
E
F
While uncovering the cover of the thermodisk, be careful
for electric shock.