SunEarth controller will switch the pump on
when the differential is 16°F. The controller
will switch the pump back off when the differ-
ential falls to 8°F. The controller also allows
you to limit the finished solar storage tank tem-
perature if desired.
The SunEarth controller maximum tank default
setting is 140°F; this setting can be adjusted as
described in the control manual.
Adjust the valve settings in accordance with
Section 6 below.
6) TWO MODES OF SYSTEM
OPERATION
Both single and two tank SolaRay AC systems
are designed to accommodate two separate
modes of operation. Your solar water heating
system can, (1) serve as a pre-heater to your
conventional water heater adding solar energy
when and as available, or (2) completely bypass
the solar collector loop and solar storage tank
and run 100% on utility energy during inclem-
ent weather or when the solar system is shut
down for maintenance.
SINGLE TANK SYSTEM MODES OF
OPERATION
6.1 Solar Preheat
Set the tank thermostat to the lowest acceptable
temperature setting. If the solar heated water
entering the tank is warmer than the thermostat-
ic set point, the electric heating elements will
not come on. If your system has an optional
time switch on the heating element, you may
preset the timer to turn the heating element on
and off at specified times throughout the day if
desired. The timer is usually set to only allow
the element to come on in the late afternoon and
night after the solar collectors are no longer able
to provide significant heat. The time switch also
can be overridden so that you operate on 100%
solar power when conditions allow.
6.2 100% Utility Power
Leave the circuit breaker to your solar storage
tank on and close the isolation ball valves in
the collector loop (COMPONENT #5 & 14,
FIGURES 15A; 15B; 16A; 16B; 17A; 17B).
In this mode of operation you must turn off the
circulation pump. To turn the pump off, change
the operational setting from automatic to “off”.
Failure to turn off the pump can quickly damage
the pump motor, shaft, bearings or impeller.
TWO TANK SYSTEM INSTRUCTIONS
6.3 Solar Preheat
Follow the instructions for the single tank
system for setting the thermostat, gas or elec-
tric heater for automatic operation. The ball
valves going to and from the solar storage tank
(VALVE # 24 & 25, FIGURES 15A; 15B; 16A;
16B; 17A; 17B) must be open while the bypass
ball valve (VALVE # 26) must be closed. See
Figure 19a, Solar Preheat.
6.4 100% Utility Power
Follow the instructions for the single tank
system for setting the thermostat, gas or elec-
tric heater for automatic operation. The ball
valves going to and from the solar storage tank
(VALVE # 24 & 25, FIGURES 15A; 15B;
16A; 16B; 17A; 17B) must be closed while the
bypass ball valve (VALVE # 26) must be open.
See Figures 19b 100% Utility Power.
7) SYSTEM SHUT DOWN AND
ISOLATION PROCEDURES
Your SolaRay AC solar water heating system
is designed so that the key components can be
easily isolated for emergency repairs or routine
maintenance. By shutting a single valve you
can isolate the entire system from the pressur-
ized cold water supply line (COMPONENT
#23, FIGURES 15A; 15B; 16A; 16B; 17A; 17B
). In the case of a storage tank or fitting leak
immediately shut this valve and call your instal-
lation contractor for service.
The collector loop can be isolated from the solar
storage tank by closing isolation ball valves
(COMPONENT #5 & 14 FIGURES 15A; 15B;
16A; 16B; 17A; 17B .) If the pressure in this
loop drops or you find a Propylene Glycol leak
P.23
