* The stagnation temperature is calculated by
extrapolating the second order collector per-
formance equation (at 317 Btu/hr.ft2 insolation
and 100ºF ambient temperature) to the x-axis
intercept. Stagnation temperatures for various
SunEarth collectors are listed at
www.SunEarthinc.com
NOTE: In addition to the collector loop expan-
sion tank a POTABLE EXPANSION TANK
MAY BE REQUIRED
by the plumbing code
on the potable piping to the solar tank if there
is a backflow preventer between the household
piping and the street mains.
4.12 Electrical and Wiring Requirements
When the electric element is used as the auxil-
iary heat source a properly licensed contractor
shall make the 230 VAC electrical connection
to the water heater or solar storage tank. If your
solar contractor is not allowed by law to make
these connections consult a licensed electrician.
Never activate the circuit breaker controlling
the electrical heating element until the solar
storage tank is completely filled with water.
This will prevent “dry firing” of the heating
element. The electrical heating element will
be destroyed almost instantaneously if not
completely submerged in water when activated.
Make sure the water heater circuit breaker is off
until the solar storage tank is completely filled.
SunEarth recommends the use of a 115 VAC
differential control with a factory installed six
foot line cord. The installation requires one 115
VAC outlet to be installed near the solar stor-
age tank. Plug the control into the outlet. The
circulation pump line cord is plugged into the
receptacle on the controller. A 230 VAC con-
trol and circulation pump may be substituted.
P.16
COLLECTOR PLUMBING - VERTICAL MOUNT
fig. 13
