About Fan Control; System Connection Example - Mitsubishi Electric PFAV-P250VM-E Manuel D'installation

7.6. About fan control

The fan stops during defrosting. Refer to the following table for details on related switch settings and operation.
Specification
• Forced heating operation
• Fan operation during an error
Fan operation during defrosting
*1: Setting at the time of shipment
* If the fan is set to ON during defrosting, the room temperature may be remarkably reduced because cold air is blown into the room and recovery from defrosting is
slower, so use the unit with SW 3-4 set to OFF.

7.7. System connection example

Precautions
1. Set consecutive numbers for the addresses of indoor units.
2. Do not connect terminal blocks TB5 on the indoor units that are connected to an outdoor unit in a different refrigerant circuit with each other.
3. Three or more MA remote controllers cannot be connected to indoor units in the same group. If three or more indoor units are included, ensure that connecting MA
remote controllers must be 2 or less.
Allowable length
a. Indoor and Outdoor Transmission Cable
Maximum length (At least 1.25 mm²)
• L1 (L2)  200 m
• L1 + L2  200 m
b. Transmission Cable for Centralized Control
No connection is required
c. MA Remote Controller Cable
Total length (0.3 - 1.25 mm²)
m1, m2 +m3 (m1+m2)  200 m
* The figures in the parentheses are applicable to the P600 model.
[Fig. 7.7.1] (P.10)
1 Indoor Unit : PFAV-P250VM-E
PFAV-P300VM-E-F
Outdoor Unit : PUHY-P250YHM-A
PUHY-P250YHC-A
2 Indoor Unit : PFAV-P500VM-E
PFAV-P600VM-E-F
Outdoor Unit : PUHY-P500YSHM-A
PUHY-P500YSHC-A
3 Indoor Unit : PFAV-P750VM-E
PFAV-P900VM-E-F
Outdoor Unit : PUHY-P750YSHM-A
PUHY-P750YSHC-A
A Group
Wiring Procedure and Address Setting Procedure
a. Indoor and Outdoor Transmission Cables
Connect terminals A and B of the terminal block for the indoor and outdoor transmission cables (TB3) of the outdoor units (OC, OS) (Note 1) and terminals A and B of
the terminal block for the indoor and outdoor transmission cable (TB5) of the indoor unit (IC) in a daisy-chain. (Non-polarized 2-wire)
* Be sure to use shielded cables.
[Shielded cable process]
With the earth of the shielded cable, connect the earth terminal of OC (
Note 1: The outdoor units OC and OS of the same refrigerant circuit system are differentiated automatically.
b. Transmission Cable for Centralized Control
This cable does not need to be connected.
c. MA Remote Controller Cables
* This cable is not needed when operation will not be performed with two remote controllers or a group.
[In the case of operation with two remote controllers]
In the case of two remote controllers, connect terminals 1 and 2 of the IC terminal block (TB15) and the terminal block of the MA remote controller. (Non-polarized 2-
wire)
* Set the connected MA remote controller as a sub remote controller using the function for switching between main and sub. (For the setting procedure, refer to the
Operation manual.)
The MA remote controller is built into the indoor unit.
d. Setting Switches
Refer to Section 7.4. "Setting addresses".
20
SW
OFF
• Disabled
• Fan stays on during an
error
(The fan will stop where
there is a fan problem or
SW1-7
communication error.)
The fan is OFF during
SW3-4
defrosting *1
B MA (Main)
) and S terminal of the IC terminal block (TB5) in a daisy chain.
Operation
ON
• Enabled
• Fan turns off during an
error *1
The fan is ON during
defrosting
C MA (Sub)
Remark
If the forced heating operation function is enabled
and when the return air temperature is 5C or
below, the unit is forced to operate in the heating
mode regardless of the selected operation mode
to prevent cold air draft.
The unit will resume operation in the selected
mode when the temperature reaches 6C or
above.
When an error occurs, the fan will stop regardless
of the outside temperature.
The fan is set to OFF at the time of shipment in
order to stop users feeling the cold air.