Johnson Controls HVWHP072B32S - Page 98

3-78
SM-18006
TROUBLESHOOTING
Yes
Yes
Set it correctly.
No
Connect them.
No
No
Is setting of DSW2
on W.S. PCB correct?
Yes
Are thermistors THM8
and THM9 (for discharge
gas temp.) connected to
THM8 (Td1) and THM9
(Td2) on W.S. PCB?
Is resistance of
discharge gas thermistors
THM8 and THM9 within
range indicated in
thermistor characteristics
graph right?
Failure of Thermistor
Failure of W.S. PCB
l
 TheRUNindicator(red)ashes.
l
 Theindoorunitnumber(refrigerantcyclenumber-addressnumber),thealarmcode,themodelcode
1
,
the model name
1
andthenumberofconnectedindoorunitsaredisplayedontheLCD.Thealarmcode
andthewatersourceunitnumber/compressornumberwithanabnormalthermistoraredisplayedonthe
7-segmentdisplayofthewatersourceunitPCB.
Note1:Exceptforsomemodels.
Thisalarmcodeisdisplayedwhenashortsensorforoneminute(0.9kΩorless)oropensensor(5946kΩor
more)isdetectedforasecondtimeduringoperation.
Cause Check Item
Action
(Turn OFF Main Switch)
Event
Faulty Discharge
Gas Thermistor
Check resistance.
Replace thermistor
if faulty.
Failure
Check wiring to
W.S. PCB.
Repair wiring and
connection.
Incorrect Connection
Replace W.S. PCB
and check operation.
Replace W.S. PCB
if faulty.
Faulty W.S. PCB
Check setting of
DSW2 on W.S. PCB.
Correctly set
DSW2 on W.S. PCB.
Incorrect Setting of DSW2 on W.S. PCB
W.S.PCB:WaterSourceUnitPCB(PCB1)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0
50
100
150
200
250
Output Voltage [VDC]
Ambient Temperature T [ºF (ºC)]
Thermistor Characteristics
Thermistor Resistance R
T
[kΩ]
116.5kΩ
41.4kΩ
17.2kΩ
8.1kΩ
1.4V
2.7V
3.7V
4.3V
0
(-18)
50
(10)
100
(38)
150
(66)
200
(93)
250
(121)
300
(149)
R
25
= 200kΩ
(When T = 77ºF (25ºC), RT = 200kΩ
B = 3920K
R
T
= R
25
• exp B(1/T[K] - 1-298)
Thermistor Resistance [kΩ] Output Voltage [VDC]
Alarm
Code
AbnormalityofThermistorforDischargeGas
TemperatureontheTopofCompressor
Model
Thermistor
Td1
(THM8)
Td2
(THM9)
(H,Y)VWH(P,R)072-120B(3,4)2S ▬
(H,Y)VWH(P,R)144-216B(3,4)2S