Johnson Controls YVAHP072B31S, Service Manual

Page: 1458 / 1796

3-144
Service Manual
TROUBLESHOOTING
(3) Check Item after Sampling Data
a. Cooling Operation (It is applicable when the outdoor temperature is higher than 59°F(15°C).)
No. Check Item Standard Causes Result
1 Is fan actually running when
Fo $LUÀRZ5DWHRI28)DQLVQRW³´" -
•
•
•
Fan Motor Failure
O.U. PCB Failure
Condenser Failure
2 Is the total of iE (I.U. Ex. Valves Opening)
abnormally low or high?
-
•
•
Low Excessive
Refrigerant
High ,QVXI¿FLHQW
Refrigerant or Excessive
Pipe Pressure Loss
3 Is TL (Liquid Pipe Temp. of I.U. Heat Exchanger)
lower than Ti (Intake Air Temp. of I.U.)?
It is normal when
TL-Ti < -9
o
F (-5
o
C).
•
•
•
TL Thermistor Failure
I.U. Ex. Valve; Fully Closed
Short-Circuit
4 Is TG (Gas Pipe Temp. of I.U. Heat Exchanger)
lower than Ti (Intake Air Temp. of I.U.)?
(It is applicable when Intake Air Temp. is 5
o
F (3
o
C).
higher than Setting Temp.)
It is normal when
TG-Ti < -9
o
F (-5
o
C).
•
•
•
TG Thermistor Failure
I.U. Ex. Valve;
Fully Closed or
Slightly Open
Short-Circuit
5 Is there any excessive difference in SH (TG-TL) of
I.U. heat exchanger among I.U.s?
(It is applicable when Intake Air Temp. 5
o
F (3
o
C).
higher than Setting Temp.)
It is normal if the
difference among
units is within
13
o
F (7
o
C).
•
•
TL/TG Thermistor Failure
I.U. Ex. Valve;
Fully Open, Slightly Open
or Fully Closed
6 Is there any I.U. with the I.U. heat exchanger
SH (TG-TL) excessively lower than the other
units’ value and is iE (I.U. Ex. Valves Opening)
lower than “5”?
It is normal if SH
of the unit is up to
-5
o
F (-3
o
C) lower
than the other units.
•
•
I.U. Ex. Valve;
Locked and Fully Open
Mismatched Wiring and
Piping
7 Is there any I.U. with the I.U. heat exchanger
SH (TG-TL) excessively lower than the other
units’ value and is iE (I.U. Ex. Valves Opening)
lower than “100”?
It is normal if SH
of the unit is up to
5
o
F (3
o
C) higher than
the other units.
•
•
I.U. Ex. Valve;
Locked and Slightly Open
or Closed
Mismatched between
Wiring and Piping
8 Is the temperature difference between I.U.s* more
than 13
o
F (7
o
C)?
* The temperature difference between I.U.s
means the following;
b3 (Discharge Air Temp.) - b2 (Intake Air
Temp.) indicated on the wired controller by
check mode.
13
o
F (7
o
C)
and over
-
b. Heating Operation (It is applicable when outdoor temperature is higher than 32°F(0°C.))
No. Check Item Standard Causes Result
1 Are oE1 and oE2 (O.U. Ex. Valves Opening)
abnormally low or high when TdSH is
59
o
F to 113
o
F (15
o
C to 45
o
C)?
-
•
•
Low Excessive
Refrigerant
High ,QVXI¿FLHQW
Refrigerant
2 Is Pd “232” to “522” psi (“1.6” to “3.6” MPa)? 232 - 522 psi
(Pd is high when the
indoor temperature
is high.)
•
•
Low Solenoid
Valve SVA Leakage
High Excessive
Gas Pipe Pressure Loss
3 Is Ps “22” to “189” psi (“0.15” to “1.3” MPa)?
22 - 189 psi
•
•
Low O.U. Short-circuit
Low/High O.U. Fan
Motor Failure,
Fan Module Failure or
Outdoor Ambient
Thermistor Failure
4 Is the temperature difference between I.U.s* more
than 18
o
F (10
o
C) when iE (I.U. Ex. Valve) is “100”?
* The temperature difference between I.U. means
the following;
b3 (Discharge Air Temp.) - b2 (Intake Air
Temp.) indicated on the wired controller by
check mode. However, this is applicable only
when b2 (Intake Air Temp.) - b1 (Setting Temp.)
is higher than 5
o
F (3
o
C).
18
o
F (10
o
C)
and over
•
•
•
Failure in PCB, Wiring,
I.U. Ex. Valve and Coil
Excessive Pipe
Pressure Loss
Thermistor Failure
for Discharge Air
NOTE:
The symbol with an underline indicates a checking item and the mark “ ” indicates checking data.