Toshiba BMS-IFMB1280U-E Installation Manual page 12

Modbus interface
Air conditioner
Modbus Master
Connect the earth wire to the
earth terminal on the chassis.
Power supply
220V-240 VAC
Connect the power supply cable
and earth wire to the terminals
using ring terminals with insulation
sleeve.
REQUIREMENT REQUIREMENT
Disconnect the appliance from the main power supply.
This appliance must be connected to the main power supply by a circuit breaker or switch with a contact separation of at least
3 mm.
Fasten the screws to the terminal with torque of 0.5 Nm.
 Wiring connection
The following describes a connection example when two or more Modbus interface units are used.
Termination resistance setting (See "6 Setting" for the setting method.)
• Set the RS-485 termination resistance to "120 ohm" for address1 (Modbus interface address SW1=1) Modbus
interface unit, and set to "open" for other units.
• Set the Uh Line Termination resistance.
Refer to "Termination resistance setting"(P.6)
Shield earthing
• The shielded wire of the RS-485 communication cable must be earthed on address 1 (Modbus interface address
SW=1) Modbus interface. Fix the shielded wire of RS-485 communication cable with metal cable clamp and
screw it to the chassis to earth it. The shielded wires must be crimped with closed end connectors on interfaces
with address of other than 1. The shielded wire ends must be insulated and left open.
• Do not connect the shield wire to the terminal block. It should be open and insulated. The shielded wire of the
Uh Line communication cable must be earthed on the air conditioner.
11-EN
To connect 2 cables,
change the preset cable
clamp to the provided one
and fix the cables with the
cable clamp as shown in
the figure left.
(50/60 Hz)
The shielded wire of the Uh
Line communication cable
must be earthed on the air
conditioner. Do not connect
the shield wire to the
terminal block. It should be
open and insulated.
SW8
1 2
Installation Manual
The shielded wire of the RS-485
communication cable must be earthed on
address 1 (Modbus interface address SW=1)
Modbus interface. The shielded wires must
be crimped with closed end connectors on
interfaces with address of other than 1. The
shielded wire ends must be insulated and left
open.
LED4 LED2
LED5 LED3
SW2 SW1
SW3
1 2 3 4
SW5 SW6 SW7
LED1
SW4