Flowserve NRS 2-4 - Manual (Page 6)

6
Explanatory Notes
System description
The level switch NRS 2-4 is an analogue electronic amplifier for the capacitance
electrode type NRG 211.
In combination with this level electrode it can detect high water level. In addition, the
level switch evaluates possible malfunction signals coming from the electrode and
monitors the electrode supply cable and can therefore be used as part of a
controlled draining system in power stations.
Scope of supply
NRS 2-4, design “c”
1 Level switch NRS 2-4
2 Guide rails
1 32 pole screw-type connector
1 Installation instructions
NRS 2-4, design “d”
1 Level switch NRS 2-4
1 Installation instructions
Function
The measuring voltage delivered by the electrode is decoded as a function of its
magnitude and indicated by LEDs when there is a malfunction in the electrode
supply cable or in the electrode and when the electrode is exposed or submerged
(high level).
In the case of a malfunction the output relay malfunction is energized. When the
electrode is submerged (high level) the output relay alarm is energized.
Optocouplers are connected in parallel and assigned to the output relays. They will
be energized in the event of a malfunction or an alarm.
Design
Design “c”
19" slide-in unit with guide rails and 32 pole screw-type connector for installation in
19" magazines to DIN 41494 part 5.
Design “d”
Spare 19" slide-in unit