1. Product Specifications
1-5-5. External water temperature sensor TW-TH16
1. Required parts for installing a external water temperature sensor
A) External water temperature sensor
B) Cable for connecting between the sensor and the unit*
C) Cable terminal for connecting to the sensor and the unit terminal block*
(Terminals for M4 screws × 4)*
* A) and B) are field-supplied.
2. Installing a external water temperature sensor
As shown in the figures below, install the sensor at the merged part of water pipes or the load-side tank.
The sensor can be installed in either the vertical or the horizontal position. When installing the sensor in the
horizontal position, make sure to place the cable-access-hole side down.
3. Wiring for a external water temperature sensor
As shown in the figures below, connect the cable to the external water temperature sensor and the terminal block in
the unit control box.
External water temperature sensor
· Resistance value: R = 15 kΩ ± 3% (0°C)
· Numerical constant of B: 3460K
On the unit side, connect the sensor cable to the terminals K1
and K2 (or K3 and K4)in the terminal block in the unit control box.
Connect the shielded cable to the ground terminal.
On the sensor side, as shown in the figure at right, run the cable
through d), c), and b), attach the field-supplied terminals for M4
screws to the cable, and then connect the terminals to the screws
e) and f) (terminal A and B).
Cut the shielded cable and leave it unconnected.
(On the unit side, the shielded cable should be connected to the
ground terminal already.)
Tighten the tightening screw d), and caulk the gap between the
tightening screw d) and cable a) to prevent water leakage.
*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.
Terminal block in the unit control box
(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.
Terminal block on the sensor
c) Washer (Inner diameter ø12)
d) Tightening screw (Inner diameter ø15)
Shielded cable (cut)
a) Cable (field-supplied)
Enlarged view of area A: Cable installation
2-core, 1.25 mm
CVVS or CPEVS
M4 screw × 3
b) Watertight sealing rubber
(Inner diameter ø11)