Mitsubishi Electric PAC-IF032B-E Installation And Operation Manual page 13

4. Electrical work
TB.143 THW1
TB.143 THW2
TB.143 TH2
TB.143 THW5
<Fig. 4.3.1>
4.3. Connecting the thermistor cables
Connect the thermistor for the FTC2B controller.
4.3.1. Connecting the refrigerant pipe temp. thermistor (TH2) cable
Connect the TH2 cable to the CN21 connector on FTC2B.
CNW12
For split Outdoor unit : Connect TH2.
For packaged Outdoor unit : It is NOT necessary to connect TH2.
CN21
When the TH2 cable is too long, connect to TH2 terminal (TB143.5-6) after cut
them to the appropriate length or bundle the excess cable outside the FTC2B unit.
Do not bind the wires in the FTC2B unit.
CNW5
<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.
4.3.2. Connecting the flow water temp. thermistor (THW1) ca-
ble 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 FTC2B.
When the THW1 and THW2 cable are too long, connect to THW1 and THW2
terminal (TB143.1-2 and 3-4) after cut them to the appropriate length or bundle the
excess cable outside the FTC2B unit. Do not bind the wires in the FTC2B 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).
4.3.3. Connecting the actual DHW tank thermistor (THW5) cable
Connect the THW5 cable to the CNW5 connector on FTC2B if the DHW tank is
available.
When the THW5 cable is too long, connect to THW5 terminal (TB143.7-8) after cut
them to the appropriate length or bundle the excess cable outside the FTC2B unit.
Do not bind the wires in the FTC2B unit.
<Thermistor position>
Place THW5 on the position where tank water temperature can be detected cor-
rectly.
It is recommended to position the thermistor at the mid height of the DHW tank (to
control DHW heating with this sensor).
It is recommended to protect the thermistor with heat insulating materials so as not
to be affected by ambient temperature.
Especially for double (insulated) tank, thermistor should be attached to the inner
side (to detect the water temperature).
Note:
Connect the terminals by using the ring terminals and also insulate the ca-
bles of adjoining terminals when wiring to TB143.
Caution:
Do not route the thermistor cables together with power cables.
The sensor part of the thermistor should be installed where user can not ac-
cess.
(It should be separated, by supplementary insulation, from areas the user
can access.)
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