Composition Rules for Intelligent Modular Units (IMUs)

Introduction

Connection of an IMU in the ULP system is simple, but must comply with the rules concerning composition, RJ45 plug/plug ULP cords, and the ULP module power supply.

General Rule: Composition of an IMU

An IMU is composed of the following two device types:

One main device (circuit breaker or switch-disconnector ) and an internal ULP communication module
One or several external ULP modules

Main device type	ULP modules
ComPacT NSX circuit breaker with BSCM circuit breaker status control module and/or MicroLogic 5, 6, or 7 trip unit ComPacT NSX switch-disconnector with BSCM circuit breaker status control module ComPacT NSX DC circuit breaker or switch-disconnector with BSCM circuit breaker status control module	0 or 1 FDM121 display 0, 1, or 2 IO modules 0 or 1 interface among: IFE interface IFE server ⁽¹⁾ IFM interface
ComPacT NS circuit breaker with BCM ULP circuit breaker communication module MasterPact NT/NW circuit breaker with BCM ULP circuit breaker communication module	0 or 1 FDM121 display 0, 1, or 2 IO modules 0 or 1 interface among: IFE interface IFE server ⁽¹⁾ IFM interface
MasterPact MTZ drawout circuit breaker with ULP port module	0 or 1 FDM121 display 0, 1, or 2 IO modules 0 or 1 interface among: IFE interface IFE server ⁽¹⁾ EIFE embedded Ethernet interface IFM interface (LV434000 only)
MasterPact MTZ fixed circuit breaker with ULP port module	0 or 1 FDM121 display 0, 1, or 2 IO modules 0 or 1 interface among: IFE interface IFE server ⁽¹⁾ IFM interface (LV434000 only)
(1) One IFE server with stacked IFM interfaces: In terms of power supply, the maximum number of IFM interfaces stacked to one IFE server is 11 in order to limit voltage drop. In terms of Modbus-SL communication, it depends on the performance requirement. As it takes approximately 500 ms at 19,200 Baud per device to refresh 100 registers, the more interfaces added the longer the minimum refreshment period. The minimum refreshment period depends on the number of IFM interfaces stacked to one IFE server. Multiply the time to refresh one device by the number of devices to find the minimum refreshment period expected in the application. For instance, an installation with eight IFM interfaces stacked to one IFE server at 19,200 Baud would take approximately 4 seconds to be read. For good communication performance, a maximum of eight IFM interfaces stacked to one IFE server is recommended.

These examples illustrate the composition rules for an IMU.

A	ComPacT NSX , ComPacT NS , or MasterPact NT/NW circuit breaker
B	MasterPact MTZ circuit breaker with ULP port module
C	MasterPact MTZ drawout circuit breaker with ULP port module and EIFE interface

General Rule: Order of ULP Modules in an IMU

Connect the ULP modules in a single IMU in any order. Base the connection on the ULP cable recommendations and the desired layout for the ULP modules in the electrical equipment.

A	ComPacT NSX , ComPacT NS , MasterPact NT/NW , or MasterPact MTZ circuit breaker

General Rule: ULP Line Termination

The ULP modules placed at the end of the ULP line must have a ULP line termination (part number TRV00880) on the unused ULP RJ45 connector.

Example of ULP line termination on IFE interface:

Place the ULP modules which have an internal ULP line termination at the end of the ULP line, that is:

BSCM module or MicroLogic 5, 6, or 7 trip unit for ComPacT NSX circuit breakers.
BSCM module for ComPacT NSX DC circuit breakers.
BCM ULP module for ComPacT NS or MasterPact NT/NW circuit breakers.
ULP port module for MasterPact MTZ circuit breakers.

NOTE: In an architecture with an EIFE interface connected to a ULP port module, the ULP port module is the end of the ULP line.

General Rule: Cables to Interconnect IMUs on Communication Networks

Do not connect the IMUs to one another with ULP cords.

Use only the Ethernet cable to interconnect IMUs connected to an Ethernet network.

A	ComPacT NSX , ComPacT NS , MasterPact NT/NW , or MasterPact MTZ circuit breaker

Use only the Modbus cable or stacking accessory to interconnect IMUs connected to a Modbus network.

A	ComPacT NSX , ComPacT NS , MasterPact NT/NW , or MasterPact MTZ circuit breaker

General Rule: Limitation of Number of MasterPact MTZ and ComPacT NSX Circuit Breakers

In case of floating power supply and when no IFM interface with part number TRV00210 is installed in the ULP system, the number of MasterPact MTZ and ComPacT NSX circuit breakers is limited by earth leakage currents as described in the following tables.

The limitation is valid for all MasterPact MTZ and ComPacT NSX circuit breakers used with a ULP connection.

Limiting the maximum number of IMUs on the same external DC power supply limits the cumulated leakage currents under 0.5 mA (human sensitivity level) or 3.5 mA (class I equipment).

Number of MicroLogic trip units or control units in the case of 0.5 mA leakage current maximum:

Ue (V L-N / U L-L) (Vac)	Maximum number of MicroLogic X control units without VPS power supply ( MasterPact MTZ circuit breakers)	Maximum number of MicroLogic X control units with VPS power supply ( MasterPact MTZ circuit breakers)	Maximum number of MicroLogic trip units (ComPacT NSX circuit breakers)
66 / 115	144	23	66
127 / 220	75	12	34
230 / 400	41	6	19
347 / 600	27	4	12
400 / 690	24	9	11
1,000	16	6	0

Number of MicroLogic trip units or control units in the case of 3.5 mA leakage current maximum:

Ue (V L-N / U L-L) (Vac)	Maximum number of MicroLogic X control units without VPS power supply ( MasterPact MTZ circuit breakers)	Maximum number of MicroLogic X control units with VPS power supply ( MasterPact MTZ circuit breakers)	Maximum number of MicroLogic trip units (ComPacT NSX circuit breakers)
66 / 115	344	57	156
127 / 220	180	29	81
230 / 400	99	16	44
347 / 600	66	10	29
400 / 690	57	23	26
1,000	39	16	0

General Rule: Power Supply Through the ULP Cord

Only one device can be powered through the ULP cord. This device must be at the end of the ULP line. It can be done only for the following devices:

FDM121 display.
BSCM module and MicroLogic trip unit for ComPacT NSX circuit breakers.
BSCM module for ComPacT NSX DC circuit breakers.
BCM ULP module for MasterPact NT/NW and ComPacT NS circuit breakers.

Example: In the diagram, the FDM121 display and the ComPacT NSX MicroLogic trip unit are powered through ULP system. The IFE server and the IO modules are connected to the power supply. As the IFM interfaces are stacked on the IFE server, they are already powered.

A	IFE server
B	IFM interfaces stacked on IFE server
C	FDM121 display
D	IO module
E	MicroLogic trip unit in ComPacT NSX circuit breaker

NOTE: The ULP port module on MasterPact MTZ circuit breaker must be connected to a 24 Vdc power supply.

Length of ULP Cords

The rules for ULP cord length are as follows:

The maximum length of the ULP cord between two ULP modules in an IMU is 5 m (16.4 ft) if one of the ULP modules does not have an external power supply.
The maximum length of the ULP cord between two ULP modules in an IMU is 10 m (32.8 ft) if both ULP modules have an external power supply.
The maximum length of all the ULP cords on a single IMU is 20 m (65.6 ft).
In the case of an installation with a withdrawable drawer, the total length of the ULP cords for the fixed part must be less than 12 m (39.4 ft). This length limitation is to ensure that the fixed part operates correctly when the drawer is drawn out.
The bending radius of the ULP cords must be 50 mm (1.97 in) minimum.

NOTE: In the following cases of device combinations with an IFE interface with part number LV434010 or LV434011, ULP total network length is limited to a maximum of 5 m (16.4 ft):

A MasterPact MTZ circuit breaker and an IFE interface.
A MasterPact MTZ circuit breaker, one IO module, and an IFE interface.
A MasterPact MTZ circuit breaker, two IO modules, and an IFE interface.

Summary of Connection Rules

Characteristic	Value
Connection	Daisy-chaining of ULP cords and ULP line termination at the end of the ULP line.
Maximum length	20 m (65.6 ft) in total for the IMU. 10 m (32.8 ft) between two ULP modules if both ULP modules have an external power supply. 5 m (16.4 ft) between two ULP modules if one of the ULP modules does not have an external power supply. 12 m (39.4 ft) for the fixed part in the case of an installation with a withdrawable drawer.
Voltage range supported	24 Vdc -10%/+10% (21.6–26.4 Vdc)
Current limitation on each ULP RJ45 port	300 mA