5. Commissioning, operation
5.2 Electrical connection
The electrical connection must only be made by qualified skilled personnel. Con-
nection details and switching functions are given on the product label. Connection
terminals and ground terminal are appropriately marked.
EN
For power ratings (see "Specifications") and for circuit protection for inductive and
capacitive loads see chapter 5.3 "Contact protection measures".
Safety instructions for installation
Install instruments in accordance with the manufacturer's instructions and the
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valid standards and regulations.
Only connect circuits with the same voltage and type of protection to the switch
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contacts and connecting cables.
Only for switch contact models 821 and 851: Limit the maximum current, using
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external measures, to a value of ≤ 1 A per circuit.
Size the connecting cables for the largest current strength in the circuits and
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ensure sufficient UV resistance and mechanical stability.
Voltages greater than AC 50 V or DC 120 V:
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- Do not connect circuits simultaneously with extra-low voltage circuits or with
safety extra-low voltage (SELV) or protected extra-low voltage (PELV).
- Circuits must offer a device, external to the measuring instrument, that
enables the instrument to be isolated from the electrical supply. This must be
easily accessible and be marked as the isolation device for the instrument.
- Cables for the circuit must fulfil the isolation requirements and conform to, for
example, IEC 60227 or IEC 60245.
- For protection against electric shock, connect the protective conductor con-
nection to the protective earth.
With flexible connecting cables, use isolated end splices. Max. permissible
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conductor cross-section 1.5 mm².
Connecting cables must be suited to the ambient temperature range of the
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application.
The connecting cables must also be suitable for the supplied cable gland (for
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diameter range, see below).
14
Operating instructions pressure gauges with switch contact models 821, 851 or 830 E