Panasonic 2WAY Multi - P23 Water Heat Exchanger Unit Interlock Error (for Only Water Heat Exchanger Unit

IV–102
P23 Water Heat Exchanger Unit Interlock Error (for only water heat exchanger unit)
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Error detection method
An error is detected when the following conditions are met:
• After a hot and cold water pump operation command, when the hot and cold water pump interlock signal (no
voltage, a contact) is not ON within 5 minutes.
• When the hot and cold water pump interlock signal turned ON once, but turned OFF again while the hot and
cold water pump operation signal continued.
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Troubleshooting
1
Water heat
exchanger
unit’s
electrical
box
1-1
Is the hot/cold water pump operation command wiring
connected to the auxiliary hot/cold water pump electrical
relay? (Notes 1, 3)
Yes 1-2
No
Request equipment
wiring
1-2 Is a hot/cold water pump interlock connected? (Notes 2, 3)
Yes 1-3
No
Request equipment
wiring
1-3 Are any signal lines severed, faulty or short-circuited?
Yes Repair
No 1-4
1-4
Is the power to the auxiliary equipment’s control board
switched off?
Yes Switch on the power
No 1-5
1-5
Is there any chattering in auxiliary equipment’s hot/cold water
pump electrical relay or in the hot/cold water fl ow switch?
(Note 4)
Yes
Request equipment
repair
No
Replace the water heat
exchanger unit board
Note 1: Hot/cold water pump operation command TB3: between No. 1 and No. 2 (No voltage a contact output)
Note 2: Hot/cold water pump interlock TB4: between No. 1 and No. 2 (No voltage a contact input)
Note 3: Operations are possible when there is a short-circuit between No. 3 and No. 4 on the TB3 terminal
board, but this may lead to the coolant freezing or other problems owing to a reduced fl ow volume, so
an interlock must be connected without fail.
Note 4: Switch on the fl ow switch to confi rm that the correct fl ow volume is being maintained in series with the
signals operated by the coolant pump. Check the settings for the fl ow switch.
● See “5. Reference Document” for details on the procedure for replacing the water heat exchanger unit’s
control board.
GHPtroubleshooting.indbIV‒102GHPtroubleshooting.indbIV‒102 2012/11/2611:20:162012/11/2611:20:16