Raychem HWAT-ECO Handbuch Seite 31

Fig. 14
Measurement
Instructions for the placing of the heat insulation
For problem-free operation of the self-regulating heating cables, the mate-
rial quality and thickness of the thermal insulation are in accordance with
the design parameters, and this insulation must be installed correctly.
All the parts of the pipework, including valves, wall transit points, etc.
must be fully insulated.
Operation, System start-up
1) For small installations, turn on the circuit breakers and preferably leave
the system overnight for the water to warm up and stabilise.
2) For bigger installations or for a faster start-up, first turn on the main
water heater and open the outlet/tap at the end of the pipework run until
the water feels warm and then turn on the circuit breakers.
If the piping system is closed, such as by pressure-reducing valves or iso-
lation valves, you must provide some method of pressure relief to allow
for thermal expansion of the water during heat-up.
Under normal operating conditions, the heating cables are maintenance-
free. Tyco Thermal Controls recommends that the insulation resistance
should be checked periodically and compared with the original values. If
the reading falls below the minimum value (10 Megohms) determine the
cause and rectify before re-use.
The specified maximum ambient and operating temperatures should not
be exceeded.
In the event of repair to the pipework, the heating cable must be protected
against damage. Correct functioning of the electrical protection system
should be maintained. To prevent shock or personal injury, turn off the power
at the circuit breaker before testing or working on the heating cable or piping.
Following the completion of the repair work, the circuit should once again
be tested (see page 30).
Newly installed heating cables have lower power at start-up of the installa-
tion. The nominal power will be reached after approximately 4 weeks of
continuous operation.
The maintenance temperature of should be 5°C to 10°C below the hot
water temperature in the boiler.
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