Terminal Description; Install An Expansion Module - Hach SC4500 Manual Básico Del Usuario

For AC controllers, use the relays at high voltage. For DC controllers, use the relays at low voltage.
Refer to Specifications
high and low voltage.
Relay terminal connections to the mains circuit in permanent connection applications must have
insulation rated for a minimum of 300 V, 90 °C (194 °F). Terminals connected to the mains circuit
with a power cord connection must be double insulated and rated 300 V, 90 °C (194 °F) at both the
inner and outer insulation levels.
Figure 10 Connect the relays
Terminal Description
1 Relay 2, NC
2 Relay 2, common
3 Relay 2, NO
NC = normally closed; NO = normally open

4.3.5 Install an expansion module

Explosion hazard. This manual is only for installation of the unit in a non-hazardous
location. For installation of the unit in hazardous locations, use only the instructions and
approved control drawing provided in the hazardous location installation manual.
Expansion modules with analog outputs, analog inputs and Profibus communication are available for
the controller. Refer to the documentation supplied with the module for additional information.
on page 3 for the relay specifications. Do not configure a combination of both
Table 4 Wiring information—relays
W A R N I N G
Terminal Description
4 Relay 1, NC
5 Relay 1, common
6 Relay 1, NO
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