Heating Overload Protection; Anomalous Fan Motor; Plural Unit Control - Mitsubishi Heavy Industries FDT Series Technical Manual

(15) Heating overload protection

(a) If the indoor heat exchanger temperature (detected with Th
the compressor stops. When the compressor is restarted after a 3-minute delay, if a temperature at 63°C or higher is
detected for 2 seconds continuously within 60 minutes after initial detection and if this is detected 5 times consecutively,
the compressor stops with the anomalous stop (E8). Anomalous stop occurs also when the indoor heat exchanger
temperature at 63°C or higher is detected for 6 minutes continuously.
(b) Indoor unit fan speed selection
If, after second detection of heating overload protection up to fourth, the indoor fan is set at Me and Lo taps when the
compressor is turned ON, the indoor fan speed is increased by 1 tap.

(16) Anomalous fan motor

(a)
After starting the fan motor, if the fan motor speed is 200rpm or less is detected for 30 seconds continuously and 4 times
within 60 minutes, then fan motor stops with the anomalous stop (E16).
(b) If the fan motor fails to reach at -50 rpm less than the required speed, it stops with the anomalous stop (E20).
(17) Plural unit control – Control of 16 units group by one remote controller
(a)
Function
One remote controller switch can control a group of multiple number of unit (Max. 16 indoor units). "Operation mode"
which is set by the remote controller switch can operate or stop all units in the group one after another in the order of unit
(1)
No. . Thermostat and protective function of each unit function independently.
Note (1) Unit No. is set by SW2 on the indoor unit control PCB. Unit No. setting by SW2 is necessary for the indoor unit only. In cases of the twin and
triple specification, it is necessary set for the master and the slave units. This can be selected by SW5. (All are set for the master unit at the
shipping from factory.)
SW2: For setting of 0 – 9, A – F
SW5: For setting of master and slave units
(See table shown at right.)
Signal wiring
between outdoor unit
and indoor units
Indoor unit
(2) Unit No. may be set at random unless duplicated, it should be better to set orderly like 0, 1, 2..., F to avoid mistake.
(b) Display to the remote controller
1) Center or each remote controller basis, heating preparation: the youngest unit No. among the operating units in the
remote mode (or the center mode unless the remote mode is available) is displayed.
2) Inspection display, filter sign: Any of unit that starts initially is displayed.
3) Confirmation of connected units
a) In case of RC-E5 remote controller
Pressing "AIR CON No." button on the remote controller displays the indoor unit address. If " " " " button is
pressed at the next, it is displayed orderly starting from the unit of youngest No.
b) In case of RC-EX1A remote controller
If you touch the buttons in the order of "Menu"
screen of remote controller, the indoor units which are connected are displayed.
Compressor ON
Indoor heat exchanger temperature (°C)
SW5 setting
Unit
Master unit
Slave unit a
Slave unit b
Outdoor unit
0 1 2
Remote controller wiring
R
Remote controller
-R) at 63°C or higher is detected for 2 seconds continuously,
I
Compressor OFF
56
63
Switch
SW5-1 SW5-2
OFF OFF
OFF ON
ON OFF
Refrigerant piping
4 5 6
3
(Master unit) (Slave unit a) (Slave unit b)
"Next" "Service & Maintenance"
- 303 -
'12 • PAC-T-173
F
"IU address" on the TOP