Flowserve ER 50-1 - Manual (Page 5)

5
Explanatory Notes
Description
The level electrodes ER 50- and ER 56- work according to the conductivity measurement principle.
The ER 50-/56- can signal a maximum of three levels in electrically conductive liquids:
■
Low level alarm (MIN alarm), pump ON, pump OFF with one NO contact
ER 50- for vessels up to PN 6, e. g. for condensate and low-pressure systems as well as (pressurised)
hot-water installations, concrete vessels, feedwater tanks. PN 6 flanges only available on request.
ER 56- for vessels up to PN 40, e. g. in high-pressure steam plants.
For the operation of the level electrodes ER 50- and ER 56- an external GESTA level switch is
required, e. g. NRS - for fill and discharge control with first low-level alarm, NRS -5 for fill and
discharge control with high-level alarm, NRS - as first low-level alarm and high-level alarm or NRS
-3 as water level limiter with test button.
Function
The conductivity of the liquid is used to signal the liquid level. Some liquids are conductive, which
means that they allow an electric current to flow through them. For the safe functioning of this device
a minimum conductivity of the liquid to be monitored is required.
The conductivity measurement method can detect two conditions: electrode rod submerged or
exposed, meaning switchpoint reached (or exceeded) or not yet reached. Before installation, the
length of the electrode rod must be cut to the required switching levels, e. g. for limit alarm or the
switching of a valve or pump.
Design
ER 50-1: Screwed " to EN ISO 8-, PN 6
ER 56-1: Screwed " to EN ISO 8-, PN 40
Scope of supply
ER 50-1
 Level electrode ER 50-
 Joint ring D 33 x 39 DIN 7603-.430
 Installation manual
ER 56-1
 Level electrode ER 56-
 Joint ring D 33 x 39 DIN 7603-.430
 Installation manual