Velux CLI U12 SD0W118 El B/U Installation Operation & Maintenance page 12

4. Pump station controller: Operational control center for VELUX solar
systems. All solar loop system safety devices, temperature gauges,
pressure gauges, fill valves and drain valves are housed within or
attached to the pump station controller. Consists of the following
components:
a. Solar controller: The solar controller, turns on or
off solar loop circulator depending on the heat
gained in the solar collectors. The controller will
also limit over heating in the solar collectors and
overheating in the solar storage tank.
b. Tank and heat exchanger temperature and
pressure and gauges: The temperature and
pressure gauges in the pump station controller
will show the user the actual temperature and
pressure being supplied and returned to the solar
collector and through the heat exchanger.
c. Check valves: Check valves located in the "hot" and "cold" lines of pump
station controller help minimize the convective heat loss at night when
the system is not operating. If check valves are not installed, most of
the heated energy stored during the day would be transferred back up
into the collectors and lost.
d. Collector array isolation valves:
Valves located in the "hot" and
"cold" lines of pump station
controller are used to isolate
the solar collector loop from
the solar storage tank.
e. Pressure relief valve (for
solar loop): Will release the
pressure in the solar loop when
it exceeds 82 PSI. If the valve
opens and releases fluids,
than it is recommend that
you contact your contractor
immediately.
f. System fill valve: Used to fill
the system with heat transfer
fluid and also eliminate air
from the system.
g. System drain valve: Used to
charge the collector loop with
propylene glycol, purge air
from loop and drain the solar
water heating system of heat
transfer fluid.
h. Circulator: Circulates the
heat transfer fluid from the
solar collectors into the solar
storage tank heat exchanger.
i. Ball valve (for circulator): Used to isolate the circulator pump for service
and when filling the system with heat transfer fluid.
12 – Part 3: Solar water heater system installation
a.
b. c. d.
h.
Inside a pump station controller
Pump station controller
e.
f.
g.
i.