nvent Raychem HWAT-ECO V4, Manual

Page: 30 / 140

30 | nVent.com
Fig. 14
Measurement
Instructions for the placing of the heat insulation
For problem-free operation of the self-regulating heating cables,
the material 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
For small installations, turn on the circuit breakers and preferably
leave the system overnight for the water to warm up and stabilise.
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
isolation 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. nVent 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
installation. The nominal power will be reached after approximately
4 weeks of continuous operation.
The maintain temperature of should be 5°C to 10°C below the hot
water temperature in the boiler.