IM-P481-04
CTLS Issue 4
52
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TRANSLATION RUN OVER
Note: Before actioning any maintenance observe the 'Safety information' in Section 1.
6.1
General
For maintenance of the individual components that make up the system, please see the relevant product
specific IMI’s for the components concerned.
6.2
High limit device testing
The purpose of the test is to ensure that the system operates satisfactorily when required to do so.
Method:
1. High limit set point test
- The set point of the high limit controller should be lowered, to simulate a high
temperature situation. Test personnel should ensure the high limit device operates in a satisfactory manner.
2. Electrical power failure test
- The unit should be turned off at the PLC controller switch to simulate
power failure. Examination should be made to ensure the high limit system has switched to its fail-safe
mode, isolating the primary steam supply.
Frequency
It is essential that a competent person tests the high limit device on a frequent basis. Intervals between
tests should not exceed a six month period.
We do not recommend the installation of a self-acting high limit control to the Spirax EasiheatTM system.
6.3
Scale formulation
Within open systems, where there is continual make-up water, there is a risk of scale formation. The extent
of the scale will depend largely upon the water quality, which varies greatly from area to area. A test,
conducted by a water treatment specialist, is recommended to determine the local water quality and whether
problems are foreseen.
After extended service, the plate heat exchanger can be easily dismantled for cleaning. If scale becomes
a persistent problem, regular chemical cleaning should be considered.
¾" ports are available on the secondary inlet and outlet piping to allow easy connection for CIP 'Clean in
Place' apparatus. It should be noted that raising the steam pressure could result in an increase of scaling.
6.4 Local isolator
when the control panel is switched off from mains power a padlock or similar device can be used to lock the
isolator switch by lifting the center section of red isolator to expose a locking hole.
6. Maintenance
