M. snow load, N. hail resistance, O. storage tanks – HTP SSC-119SE User Manual
Page 12: P. thermal expansion (closed loop systems)
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LP-200 REV. 3.25.14
M. SNOW LOAD
In areas prone to heavy snowfall, the solar collector(s) should ideally be installed at an angle of 50
o
or greater to help promote snow
sliding off the collectors. In addition, it is advisable to raise the lower collector frame off the roof surface 6
– 8 inches or higher. Doing
this places the collector above moderate snowfall accumulation and allows drifting snow to more easily slide out from under the
collector, which helps ensure that snow does not cover the collector array.
Please refer to local regulations regarding snow loading precautions.
N. HAIL RESISTANCE
Solar collectors are surprisingly strong and able to handle significant impact stresses once installed. Testing and impact stress
modeling proves that when installed at an angle of 40
o
or greater, collectors are able to withstand impact from hail larger than 1” in
diameter. The ability of collectors to withstand hail impact is greatly influenced by the angle of impact, so installing the collectors at low
angles does reduce their impact resistance.
O. STORAGE TANKS
It is recommended that the lever on the pressure and temperature relief valves (PTRV) on main pressure hot water storage tanks be
operated once every 6 months to ensure reliable operation. It is important to raise and lower the lever gently, and be careful as the
water released will be HOT. Failure to operate the PTRV on a regular basis could lead to failure of the component and the possibility of
the storage tank exploding.
It is recommended, and may also be a local regulation, that, in order to expel water safely, the PTRV have a copper pipe connected
and run to an appropriate drainage location. The PTRV and drain outlet pipe must not be sealed or blocked.
NOTE: If the water heater is left in an operating condition and not used for two weeks or more, a quantity of highly flammable hydrogen
may accumulate in the top of the water cylinder.
To dissipate hydrogen safely, it is recommended that a hot water tap be turned on for several minutes at a sink, basin, or bath, but not a
dishwasher, clothes washer, or other electrical or heat producing appliance. During this process, there must be no smoking, open
flame, or electrical appliance operating nearby. Hydrogen discharged through the tap will sound like air escaping. Failure to dissipate
hydrogen properly could result in explosion and fire, serious property damage, severe personal injury, or death.
P. THERMAL EXPANSION (CLOSED LOOP SYSTEMS)
As water is heated, it expands. This is known as thermal expansion. Thermal expansion can cause premature component failure. Such
failures ARE NOT covered under product warranty.
An expansion tank, properly sized for your solar system, should be installed to control thermal expansion. Refer to expansion tank
manufacturer’s specifications for proper sizing guidelines.