Mitsubishi Electric e Series Service Handbook page 53

[ II Restrictions ]
[6] Installing the external water temperature sensor TW-TH16
1. Parts that are required to install an external water
temperature sensor
(1) External water temperature sensor
(2) Wiring to connect the sensor and the unit*
(3) Wiring terminals to connect the wiring to the sensor and
the terminal block on the unit
(Four for M4 screws)*
*Items (1) and (2) are field supplied.
2. Installing the external water temperature sensor
• Install the external water temperature sensor where
the water pipes merge or on the load-side tank as
shown in the figure at right.
• Install horizontally or vertically on top of the pipe.
• When installing horizontally, make sure the wire faces
down.
3. Wiring the external water temperature sensor
Connect the external temperature sensor wiring to the terminal block in the control box on the unit as shown in the
figure below.
External water temperature sensor
Sensor wire
157
Sensor
Sensor properties
· Resistance: R=15KΩ±3% (0 °C)
· B-constant: 3460K
Connect the sensor wiring to terminals KT11 and KT21 (or KT31 and
KT41) of the terminal block in the control box on the unit.
Connect the shield to the earth terminal.
Thread the wire to the external water temperature sensor through
parts 2) through 4) as shown in the figure at right. Attach M4 terminals
(field-supplied) to the wires, and connect them to 5) and 6) (terminals
A and B).
Cut the shield wire. Do not connect it to the terminal. (Connect the
shield on the unit side to the ground terminal.)
After the wire is connected, securely tighten the tightening screw 4) ,
and then caulk the gap between the wire 1) and the tightening screw
to keep water from entering.
*1 In a multiple module connection system, install the temperature sensor where the cold/hot water from each module is sufficiently
mixed to provide a representative temperature.
*2 The temperature sensor must be installed on a pipe between the outlet of the unit and the entrance to the load-side system.
HWE20010
Terminal block in the control box on the unit
KT11 (KT31) KT21 (KT41)
Control box
Note
42 54
20 12
R 1/2
A
Wire specifications
Wire size
Type
Maximum length 20 m
Vertical installation
(Note)
Run the sensor wiring at least 5 cm away from any wire that
carries a voltage of 100 V or more, and do not put the sensor
wiring in the same conduit tube with it.
Unit
6)
Terminal block for connection to the sensor
Detailed view of the area labeled "A" in the figure above
- 44 -
2-core cable Min. 1.25 mm
CVVS or CPEVS
Horizontal installation
M4 screws × 3
Terminal screws
5)
2) Water-sealing rubber
(Internal diameter ø11)
3) Washer (Internal diameter ø12)
4) Tightening screw
(Internal diameter ø15)
Shield (to be cut)
1) Field-supplied wire
2
GB