Flowserve SRL63-A User Manual
GESTRA Steam Systems
SRL 63-a
Installation Instructions 818588-00
Logic Unit SRL 63-a
Contents
Page
Important Notes
Usage for the intended purpose...............................................................................................................4
Safety note..............................................................................................................................................4
ATEX (Atmosphère Explosible) .................................................................................................................4
Explanatory Notes
Scope of supply.......................................................................................................................................5
Description..............................................................................................................................................5
Function..................................................................................................................................................5
Technical Data
SRL 63-a.................................................................................................................................................7
Name plate / marking..............................................................................................................................8
Dimensions .............................................................................................................................................8
Installation
Installing the logic unit SRL 63-a.............................................................................................................9
Functional Elements
SRL 63-a.................................................................................................................................................9
Electrical Connection
Connecting the terminal strips...............................................................................................................10
Tools.....................................................................................................................................................10
Wiring diagram of logic unit for monitoring SRL 63-a.............................................................................11
Basic Setting
Factory setting ......................................................................................................................................12
Start-up, Operation, Alarms and Testing
SRL 63-a...............................................................................................................................................12
Troubleshooting
Fault finding ..........................................................................................................................................15
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Contents
Page
Appendix
Decommissioning................................................................................................................................. 15
Disposal ............................................................................................................................................... 15
CE Declaration of Conformity ................................................................................................................ 15
TÜV approval ........................................................................................................................................ 16
3
Important Notes
Usage for the intended purpose
The logic unit SRL 63-a may be used in steam boiler plants only in conjunction with external low-level
alarms or high-level alarms for monitoring the separate flushing of the connecting lines to the measuring
pot.
Any other use is deemed as not being in compliance with the intended purpose. The user shall be solely
responsible for the associated risks. The manufacturer shall not be liable for any damage resulting from
improper usage.
Safety note
The equipment must only be installed and commissioned by suitably qualified staff.
Maintenance and service work must only be performed by adequately trained persons who have a recognized level of competence.
Danger
The terminal strip of the logic unit SRL 63-a is electrically live during operation!
Because of the electrical currents which may flow, serious injuries are possible!
Before working on the terminal strips, always ensure that the unit is de-energized!
ATEX (Atmosphère Explosible)
In accordance with the European Directive 94/9/EC, the unit must not be used in potentially explosive areas.
4
Explanatory Notes
Scope of supply
SRL 63-a
1 Logic unit for monitoring, in a field case for wall mounting
1 Installation manual
Description
For the installation of low-level limiters of "high-integrity design" in measuring pots mounted outside of
the boiler, it is imperative that the periodic purging of the connecting lines to the boiler be monitored properly.
To achieve this, the connecting lines are shut off one after the other at defined intervals and the measuring
pot is drained.
The logic unit SRL 63 monitors compliance with the preset times and the sequence of valve operations; in
addition, it bypasses the low-level limiter to ensure that the system is not shut down during purging.
The logic unit for monitoring the purging cycle consists of a compact PLC, a safety time-lag relay and a
coupling relay. The design complies with prEN 50156.
Function
Fig. 1 depicts a system with a level electrode in the boiler and the second electrode in an
external measuring pot.
Level switch
NRS 1-7/9
Level electrode
NRG 1x-11,
NRG 16-36
Level switch
NRS 1-7/9
D
E
Logic unit
SRL 63-a
Fig.1
F
Safety
circuit
5
Explanatory Notes – continued –
Function – continued –
The logic unit monitors the following times:
■ Interval time: This is the time interval at which, depending on the mode (24h / 72h operation), the con-
necting lines have to be purged.
■ Standby period: The purging process must be initiated during this time. The standby period begins
when the interval time has elapsed.
■ Purging time: During this period, the purging process must be performed through actuation of the
valves. Actuation of the valves is signalled by means of the limit switches; similarly, when the electrode
of the low-level limiter is exposed, this is sensed through the output contact of the corresponding level
switch. If a signal is not received within the purging time, the safety circuit is opened. Since a low-level
limiter may be bypassed for a maximum of 5 minutes, monitoring of the purging time is a safety-relevant function.
The interval time is started when the logic unit is switched on. The display of the PLC shows the full hours
of the remaining time. This can be synchronized at any time by closing an interconnection valve (E or D),
i.e. the purging time begins and the interval time is reset to its initial value (e.g. 24h, 72h etc.).
During operation, the standby period is started at the end of the interval time, which is immediately reset
to its initial value (e.g. 24h, 72h etc.). The PLC then starts the purging time when an interconnection valve
(E or D) leaves the end position "Open".
During the purging time, the output contact of the low-level limiter is bypassed. This bypass is triggered
by the undelayed contact of the safety time-lag relay and limited to 5 minutes by the delayed contact of
this relay.
Once all valves signal that they have reached their initial positions and the level switch of the low-level
limiter senses that the level electrode is exposed, the purging process has ended and the bypassing of the
low-level limiter is terminated.
In the event that the mains supply fails during the purging time, the bypassing of the low-level limiter is
cancelled and the safety circuit is opened. If the mains supply is switched on again, the bypass remains
deactivated and the safety circuit is only closed again after the purging process has been completed properly.
Expiry of the purging time and standby period, as well as deactivation of the safety circuit, are indicated
by means of pilot lamps.
Note
The safety circuit is opened when the standby time or the purging time is exceeded, and it
is only closed again when the purging process has been completed properly.
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