Mitsubishi Electric PVFY Series Technical & Service Manual page 17

7-2. Fan Motor Troubleshooting
All Models
If the motor rocks back and forth on start up, this is normal―do not replace the motor.
The motor may surge if operating outside the design static pressure range. Verify that the system design static
matches the selected motor static pressure settings.
The system is noisy and does not change speeds based on commands from the remote controller or the indoor unit is
going into freeze protection cycle.
Check to make sure the airflow settings are correct for the installation per the indoor unit specifications. First remove the system
filter and check that all dampers and diffusers are open. If after removing the filter this corrects the problem, change or clean the
filter. Also, check the indoor unit heat exchanger and clean as necessary.
If none of this corrects the problem, check the static pressure of the system. The static pressure should fall within the guidelines
given on the airflow charts. If it's outside the parameters given on these charts, correct the airflow problem. Make sure the static
pressure setting on the motor matches the system requirements.
If the above checks do not solve the problem, check that the supply voltage applied to the motor is correct. Measure volt-
age at the (L), (G), (N) connector shown on the diagram below. The motor supply voltage should be + or -10% of the nominal
208/230VAC rating. If the supply voltage is not within this range, correct this before any further troubleshooting.
The motor does not run.
Check for the proper line voltage power supply and ground at the (L), (G), and (N) connections. Correct any voltage issues
before proceeding to the next step.
Speed selections on the blower motor are done by 24 volt supply to the motor terminals. The low voltage connections are pro-
grammed for the operating characteristics as shown in the chart above.
Turn the indoor unit on and set to any mode that will normally run the fan. (Heat, Cool or Fan) If there is no 24 volt power supply
between terminals 2, 3, or 4 and C common, check the wire(s) from the relays located in the control box.
If the line voltage supply is within range and 24 volts is supplied to any of the connector combinations shown in the chart above
and the motor does not operate, replace the motor.
17
Fan Relays
R1 R2 R3
High Med. Low
24 VAC to motor speeds
As shipped
.50 esp connection (P12 = .40 esp)
FAN MOTOR
Green
Blue
Red
For field selected .30 esp (P12 = .20 esp)
change connections as shown
FAN MOTOR
Green
Blue
Red
For field selected .80 esp (P12 = .60 esp)
change connections as shown
FAN MOTOR
Green
Blue
Red
Model Available Ext. Static (In. W.G.)
0.20 0.40 * 0.60
PVFY-P12
0.30 0.50 * 0.80
PVFY-P18
0.30 0.50 * 0.80
PVFY-P24
0.30
PVFY-P30 0.50 * 0.80
0.30
PVFY-P36 0.50 * 0.80
PVFY-P48 0.30 0.50 * 0.80
0.30 0.50 * 0.80
PVFY-P54
* Factory Setting
24 VAC
24 VAC Common
1 C
208/230V 60Hz
2 L
Ground
3 G
208/230V 60Hz
4 N
5
1 C
2 L
3 G
4 N
5
1 C
2 L
3 G
4 N
5
Specifications are subject to change without notice.
© 2013 Mitsubishi Electric US, Inc.