Helvar
| Data is subject to change without notice.
www.helvar.com
www.helvar.com
Helvar 458Mx Chassis: Installation Guide
6
7
A0
V
SC
B
3. Electrical Installation
WARNING:
THE SUPPLY INPUT EARTH MUST BE CONNECTED.
WARNING: BEFORE STARTING ANY ELECTRICAL WORK, ISOLATE THE
ELECTRICITY SUPPLY AT THE MAIN DISTRIBUTION BOARD.
Cable Sizes and Strip Lengths
See ‘Cable Requirements’ on page 11 for cable sizes and required strip lengths.
Mains Supply Protection
The mains supply must be externally protected by a MCB or fuse not exceeding 17 kA. The incoming
protection level must not exceed 63 A for each position. Single phase operation is limited to 125 A maximum
by the neutral terminal block rating.
Using Spring-Lever Cage Clamp Terminals
Note: The supply earth, supply neutral and output terminals are spring-lever cage clamp terminals.
1. Insert a screwdriver as far as it will go into the terminal release point.
2. Lever the screwdriver back. This opens the cage clamp.
(For output terminals, levering the screwdriver back is unnecessary).
3. With the cage clamp open, do one of the following, as appropriate:
• Insert the cable into the terminal.
• Remove the cable from the terminal.
4. Release the pressure on the screwdriver, and then remove it. This closes the cage clamp.
5. If you have inserted a cable, make sure that the connection is secure.
If you are not wiring a 458M chassis to a Helvar module via SDIM, go to section 3.2, ‘Connect Loads’ on
page 8.
An SDIM cable loom is attached to the DIN-rail inside the chassis (see ‘Wiring Diagrams’ on page 9).
This can be connected to the SDIM terminals of the module(s) to enable connection of the module(s) to
a Helvar Imagine system (see diagrams below). The eight-terminal connector block is included with the
458Mx, wired to the cable loom.
3.1 Connect SDIM Cable Loom to Modules (If Applicable)
To SDIM
terminal of
module
To SDIM
terminal of
module
To SDIM
terminal of
module
DIN-Rail inside
chassis
SDIM connections
Recommended:
Belden 8102 cable
Link for termination (because this unit is at
the end of the SDIM cable line)
SDIM Termination
If a unit is at the end of the SDIM cable line, you must link between terminals ‘TERM’ and ‘B’ for
termination.
Note: The SDIM cable line needs two terminations: one at the beginning, and one at the end.
The following figure shows how to connect a 458M3 chassis to three modules:
