Electrical Installation; Dry Run Protection - Johnson Controls SABROE WHC 2.1 Installation And Operating Manual

Mounting and connections
During pressure testing, the regulating valve (Fig. 2, pos. 18) and the solenoid valve (Fig. 2,
pos. 16) must be open.
Draining
The system must be turned off before draining as the heating element and pump may be dam-
aged if there is air in the system.
Draining can be done through the safety valve (Fig. 2, pos. 29) by turning the cap or by open-
ing one of the strainers Fig. 2, pos. 20).
Purging
The system must be purged from air. This can be done by carefully loosening the air screw (
Fig. 2, pos. 9) or by unscrewing a fitting (just a little) on one of the compressor cooling hoses. If
the water circuit in general is not free of air, it is recommended to replace the air screw (Fig. 2,
pos. 9) with an automatic air vent valve.
Warning!
Scalding risk. The water in the system is hot both during operation and standstill.

Electrical installation

If the WHC system is bought as part of a Sabroe heat pump or chiller, it is connected to the
compressor electrical panel and it requires no additional control. The circulation pump, sole-
noid valve and heating element are supplied and controlled by the regulator in the terminal
box.
If the system is bought on its own, the following requirements are strongly recommended:
• A circuit-breaker and a back-up fuse for the system should be installed so that it can be
switched off during service, maintenance and shutdown of equipment.
• A compressor running signal*. See Appendix B.
• Stop input (alarm) in the compressor controller**. See Appendices A & B.
* It is possible to use the WHC system even if a compressor running signal is not available.
However, this means that a jumper must be installed in the WHC control box (Appendix B).
Furthermore, the set point for the heating element (St1) must be set 5°K lower than the sole-
noid valve set point (St2). If not, the heating element will be on at the same time as the sole-
noid valve is energized (cooling and heating at the same time).
** If the alarm signal for the WHC control box is not connected to the compressor controller,
the compressor will not be protected against failure in the cooling/heating circuit.
Supply voltage: 1 x 230 V +/-10%, 50/60 Hz
Output: 1100 W
Max. fuse: 6 amp

Dry run protection

The system is protected against dry running by a flow switch (Fig. 2, pos. 4).
If the water supply fails, the run signal to the Unisab compressor controller is disconnected,
and so is the power to the heating element (Fig. 2, pos. 13).
For further description of the flow switch, see Appendix F.
Installation and operating manual - Sabroe WHC circulation system
011162 en 2021.05 11/17