4Manual maxGUARD2526740000/02/03.2018
2 Safety | General safety notes
2 Safety
This section includes general safety notes on handling prod-
ucts belonging to the maxGUARD family. Specic warnings
for specic tasks and situations are given at the appropriate
places in the documentation. Failure to observe the safety
notes and warnings may lead to personal injury and damage
to property.
All work may only be carried out by trained
electricians who are familiar with the safety
standards that apply to electrical engineering.
2.1 General safety notes
Work on the maxGUARD products may only be performed
by qualied electricians with the support of trained persons.
As a result of their professional training and experience, an
electrician is qualied to perform the necessary work and
identify any potential risks.
Before any work is carried out on the products (installa-
tion, maintenance, retrotting) the power supply must be
switched off and secured against being switched on again.
maxGUARD products do not contain any modules or compo-
nents that can be serviced by the user. If faults connected to
a maxGUARD product cannot be rectied using the recom-
mended measures (see chapter 11), the product in question
must be sent to Weidmüller. Weidmüller assumes no liability
if the product is tampered with!
Electrostatic discharge
maxGUARD products can be damaged or destroyed by elec-
trostatic discharge. When handling the products, the neces-
sary safety measures against electrostatic discharge (ESD)
according to IEC61340-5-1 and IEC61340-5-2 must be
observed. The packing and unpacking as well as the assem-
bly and disassembly of a device may only be carried out by
qualied personnel.
Open equipment
maxGUARD products are open equipment that may only be
installed and operated in lockable housings, cabinets or elec-
trical operations rooms. Only trained and authorised person-
nel may access the equipment.
The standards and guidelines applicable for the assembly
of control cabinets and the arrangement of data and supply
lines must be complied with.
Fusing
The operator must set up the equipment so that it is protect-
ed against overloading. The upstream fuse must be designed
such that it does not exceed the maximum load current.
The maximum permissible load current of the maxGUARD
products can be found in the technical data. The operator
must decide whether additional surge protection is required
according to IEC 62305. Voltages that exceed +/-30V may
cause the destruction of the modules.
Earthing
Products belonging to the maxGUARD family may be used
for earthed and non-earthed control voltage distributors.
Products belonging to the maxGUARD family do not have
a designated earth connection. Further information can be
found in section 4.5.
2.2 Intended use
maxGUARD is an electronic load monitoring system with
integrated potential distribution. It is used for the selective
overload and short-circuit monitoring of 24VDC control
circuits in the eld of programmable controllers or similar
control systems. Electronic load monitoring devices are used
for line protection. In case of a fault, the affected circuit is
switched off. The wire cross-section has to be dimensioned
according to the internal fuse (see section3.5).
The system must be operated with 24VDC safety extra-low
voltage (SELV, 18–30VDC) or protective extra-low voltage
(PELV).
An AMG ELM electronic load monitoring device can only
be operated in conjunction with a power-feed unit (AMG
FIM-0..., AMGFIM-C...). The potential distributors of the
maxGUARD family can be used for contact replication of the
load monitor output. Only Weidmüller ZQV4N cross-connec-
tors may be used for connections within a station.
All products belonging to the maxGUARD family are intend-
ed for use in equipment or machinery installed in enclosed
areas.
Installation in a suitable enclosure provides adequate pro-
tection against contact with live parts and also against the
ingress of dust and water (e.g. control cabinet, panel, con-
sole or similar). Mounting is only permissible on a prole
rail made of steel or galvanised steel in accordance with EN
60715 (TH35-7.5, e.g. Weidmüller TS35X7.5).
The products described in this manual may only be used for
the intended applications. If used for any other purpose, the
protective measures of the product may be rendered ineffec-
tive.
Any intervention in the products’ hardware or software other
than described in this manual may only be performed by
Weidmüller.
Observance of the documentation is also part of the intend-
ed use.
