Toshiba BMS-IFMB1280U-E Installation Manual page 11

Modbus interface
When connecting to a previous model light commercial, air to air heat exchanger, air to water
heat pump, or general purpose equipment control interface
Follow the wiring specifications in the table below even when there is a mix of U series and non-U series in the connected indoor
units or remote controllers.
Wiring specifications
Item
Wire diameter
Wire type
Wire types that can be used
REQUIREMENT REQUIREMENT
When wiring the control wiring between indoor and outdoor units (Uv line)/control wiring between outdoor units (Uc line) and the
central control wiring (Uh line), use the same wire type and diameter for each line.
Using a mixture of different wire types and diameters may cause a communication error.
System diagram
Central control
LINK (Uh)
device
U3 U4
U 3
Outdoor unit
U3 U4
and Other
U1 U2
U 2
Indoor unit *
U1 U2
U 4
Hydro unit
Uv
<U series>
Remote
controller *
* The wiring specifications in the system diagram above are the same even when the indoor unit or remote controller are other
than the U series.
U 4
Light Commercial
U 4
U5 U6
TCC-LINK
U 4 U 4
adapter
A B A B
U 6 U 6
Communication line
Central control wiring (Uh line)
1.25 mm 2 (up to 1000 m)
2.0 mm 2 (up to 2000 m)
2-core, non-polar
Shielded wire
[Central control wiring (Uh line)]
L1 = Up to 2000 m
[Control wiring between indoor and outdoor units
(Uv line)/Control wiring between outdoor units (Uc line)]
L2 = Up to 1000 m
Air to Water
Heat Pump
Uh
4
A B
U 6
Installation Manual
U3 U4 U3 U4
General purpose
Air to air heat
equipment
exchanger
control
interface
10-EN