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ESIE15-08B
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Part 2. Troubleshooting
4. Component checklist - Water Circuit
19/07/16
Page 71
Daikin Altherma Monobloc CA
The Table 2-1 on page 71 must be used to compare the measured resistance with the correct resistance for the measured
temperature with a contact thermometer.
1.
Switch off the Daikin Altherma Monobloc CA via the user interface.
2.
Switch off the Daikin Altherma Monobloc CA with the field supplied circuit breaker.
3.
Remove the hydrobox top plate assembly, refer to
"Removing the hydrobox top plate assembly" on page 110
4.
Remove the hydrobox front plate, refer to
"Removing the hydrobox front plate" on page 111
5.
Remove the switch box cover.
6.
From the Table 2-1 on page 71, select the thermistor that must be checked.
7.
Measure the temperature of the thermistor using a contact thermometer.
8.
Unplug the connector from the appropriate PCB and measure the resistance between the pins listed in Table 2-1 on page 71.
-
Compare the measured resistance with the range determined by the lower and higher temperature in Table 2-2 on
page 72.
9.
If the measured resistance does not match the listed value, the thermistor must be replaced, refer to
E.g. thermistor R4T (A1P):
•
Measured temperature with contact thermometer: 23.1°C.
•
Unplug the sensor and measure the resistance between X8A: 1-2: 21.86 k
Ω
.
•
The resistance values are defined by Table 2-2 on page 72:
-
Resistance at 23°C: 21.85 k
Ω
.
-
Resistance at 24°C: 20.90 k
Ω
.
•
The measured value 21.86 k
Ω
is inside the range, thermistor R4T (A1P) passes the check.
Table 2-1: Thermistors
Electrical check
I
NFORMATION
If a thermistor check fails, replace the thermistor.
W
ARNING
: R
ISK
OF
F
IRE
•
When reconnecting a connector to the PCB, do not apply force or damage the connector or the connector pins on
the PCB.
I
NFORMATION
All thermistors have a tolerance of 5%.
I
NFORMATION
The user interface “6.1. Sensor Information” allows to monitor most thermistors.
If the measured resistance of the thermistor matches the temperature measured with the contact thermometer but the
temperature for the corresponding thermistor is not correct on the user interface display, replace PCB A1P.
Thermistor
Processed
on PCB
Connector: pin
Type
Description
R1T
A1P
X5A: 1-2
1
Outlet water after PHE
R1T
A2P/A5P
X2M: 20-21
1
Ambient sensor user interface