Mitsubishi Electric PAC-IF051B-E Installation Manual page 63

. Multiple outdoor units control
.4 Main controller wiring
(a) Wire the main controller to TBI.2 RC terminals on the master unit. The main controller must NOT be connected to a slave unit.
(b) Use the daisy chain wiring method to wire the master unit and slave units by connecting TBI.2 RC terminals. *1
*1 The maximum length between each units wiring is 10 m. The maximum length of total daisy-chain wiring is 500 m.
PAC-SIF051B-E
Main controller
1 2 3 4 5 6 7 8
Max.
500 m
Slave units
Note: Wiring for main controller cable and daisy chain cable shall be (5 cm or more) apart from power source wiring so that it is not influenced by electrical noise
from power source wiring. (Do NOT insert main controller cable and power source wiring in the same conduit.)
.5. Connecting the thermistor cables
Connect the thermistor for the FTC4 (Slave) controller.
.5.1. Connecting the refrigerant pipe temp. thermistor (TH2) cable
Connect the TH2 cable to the CN21 connector on FTC4 (Slave).
For split Outdoor unit : Connect TH2.
For packaged Outdoor unit : It is NOT necessary to connect TH2.
When the TH2 cable is too long, bundle the excess cable outside the FTC4 (Slave) unit.
Do not bind the wires in the FTC4 (Slave) unit.
<Thermistor position>
Place TH2 on refrigerant piping ( liquid side).
It is recommended to protect the thermistor with heat insulating materials so as not
to be affected by ambient temperature.
Note: Be sure to place TH2 where it correctly detects refrigerant piping temp. (liquid side).
Because;
(1) TH2 is required to detect heating subcool correctly.
(2) Refrigerant temperature of water-to-refrigerant heat exchanger also needs
to be detected for protection purpose.
.5.2. Connecting the flow water temp. thermistor (THW1) cable
and the return water temp. thermistor (THW2) cable
The THW1 and the THW2 cables share a connector, and the connector connects to
CNW12 connector on FTC4 (Slave).
When the THW1 and THW2 cables are too long, bundle the excess cables outside the FTC4 (Slave) unit.
Do not bind the wires in the FTC4 (Slave) unit.
<Thermistor position>
Place THW1 on water piping (water outlet side) after booster heater, and THW2 on the water inlet side.
It is recommended to protect the thermistor with heat insulating materials so as not to be affected by ambient temperature.
Note: Be sure to attach THW1 where it correctly detects Flow temp. (water oulet side). Fore more details, see Page 6.
Caution:
Do not route the thermistor cables together with power cables.
The sensor part of the thermistor should be installed where user can not access.
(It should be separated, by supplementary insulation, from areas the user can access.)
Master unit
TBI.2 (RC)
9 10 11 12 13 14
Max. 10 m
1 2 3 4
TBIN (RC)
Max. 10 m
1 2 3 4
TBIN (RC)
1 2 3 4
Hydrobox (with FTC4 (Master) that is set as slave)
Master unit
TBI.2 (RC)
1 2
TBI.2 (RC)
1 2
Max.
500 m
TBI.2 (RC)
1 2
Slave
units
1 2
< Fig. .4.1>
RC
Main controller
3 4 5 6 7 8 9 10 11 12 13 14
3 4 5 6 7 8 9 10 11 12 13 14
3 4 5 6 7 8 9 10 11 12 13 14
3 4 5 6 7 8 9 10 11 12 13 14
IN2
Connector CN21
Connector CNW12
<Fig. .5.1>
Max. 10 m
Max. 10 m
3