SunEarth SolaRay 2 User manual

2

SOLARAY 2
DOMESTIC SOLAR WATER
HEATER SYSTEM
INSTALLATION, OPERATION AND MAINTENANCE MANUAL
The SolaRay 2 domestic solar water heating system has gone through an extensive design, technical and per-
formance review by the Solar Rating & Certification Corporation (SRCC). The installation of your SolaRay
2 system is intended to be executed by properly licensed and experienced professional contractors in accor-
dance with SRCC Standard OG-300, “Operating Guidelines and Minimum Standards For Certifying”, and
shall conform to applicable federal, state and local regulations, codes, ordinances and standards governing the
installation of solar water heating systems.
The solar energy system described by this manual, when properly installed and maintained, meets the mini-
mum standards established by the SRCC. This certification does not imply endorsement or warranty of this
product by the SRCC.
OG-300 system certification is granted to SunEarth by the SRCC. It may not be used for any commercial pur-
pose without the prior written consent of SunEarth. SunEarth must approve any deviation from the materials
and methods described in this manual in writing.
SunEarth SolaRay 2 solar water heating systems can be protected against freeze damage to temperatures as low
as -60°F (-51°C). This system should not be installed in any area that has experienced ambient air tempera-
tures below -60°F. Use Table 4, Section 4 of this manual to determine the required concentration of propylene
glycol and distilled water to provide adequate freeze protection in your specific climate.
Propylene Gycol heat transfer fluid shall be used in this system as the primary freeze protection agent.
Unauthorized fluid substitutions can result in a threat to health, welfare and safety and may cause the system
piping to freeze.
All component warranties, expressed or implied, are voided if uninhibited propylene glycol, potable or dis-
tilled water are substituted for the specified heat transfer fluid described in this manual, or if the heat transfer
fluid is not maintained in accordance with the manufacturers specific instructions.
Freeze tolerance limits are based upon an assumed set of environmental conditions. Extended periods of cold
weather, including ambient air temperatures above the specified limit may cause freezing in exposed parts of
the system. It is the owner’s responsibility to protect the system in accordance with SunEarth’s instructions if
the ambient air temperature approaches the specified freeze tolerance limit.

P.a4
TABLE OF CONTENTS
1) Introduction.......................................................................................3
2) System Description and Operational Principle..............................4
3) Installation Requirements - General...............................................5
4) Installation Requirements - Specific...............................................7
5) Start Up Procedures........................................................................22
6) Modes of System Operation...........................................................23
7) System Shut Down and Isolation Procedures...............................23
8) Summer Vacation Procedures........................................................24
9) Maintenance and Troubleshooting................................................26
10) SolaRay 2 System Component Parts .............................................28
11) Estimated Component Life.............................................................30
12) System Operating Parameters........................................................30
Appendix A. Approved Primary Components......................................32
Appendix B. Pump Sizing Guidelines....................................................35
AppendixC. System and Component Labels.........................................36
Appendix D. Collector Specification Sheets..........................................38
Appendix E. Heat Transfer Fluid Data Sheet.......................................40
Appendix F. SunEarth Collector Warranty Statement.......................42
Appendix G. SRCC OG-300 Certified System Model Numbers........44
Appendix H. Supplier and Service Contact Information....................47

P.1
Time/Temperature Relationship in Scalds
Temperature Time To Produce a Serious Burn
120°F More than 5 minutes
125°F 1½ to 2 minutes
130°F About 30 seconds
135°F About 10 seconds
140°F Less than 5 seconds
145°F Less than 3 seconds
150°F About 1½ seconds
155°F About 1 second
Table courtesy of Shriners Burn Institute
The chart shown above may be used as a guide
in determining the proper water temperature for your home.
!
DANGER: Households with small children, disabled,
or elderly persons may require a 120°F or lower thermostat
setting to prevent contact with “HOT” water.
NOTICE: Mixing valves should be installed to reduce the
point of use water temperature by mixing hot and cold water
in branch water lines. Contact a licensed installer or the local
plumbing authority for further information.
The temperature of the water in the water heater can be regu-
lated by setting the temperature dial of the adjustable surface
mounted thermostat locatedbehindthe jacket access panel.
This thermostat controls the
water heater’s heating ele-
ment only. (A separate ther-
mostat should be utilized in
monitoring the temperature
from the collector).
To comply with safety reg-
ulations the thermostat is
factory set at 120° F or less
where local codes require.
!
DANGER: Hotter water increases the potential for Hot
Water SCALDS.
°
!
DANGER!
WATERTEMPERATURE SETTING
Safety and energy conservation are factors to be considered when selecting the water
temperature setting of water heater’s thermostat. Water temperatures above 125°F
can cause severe burns or death from scalding. Be sure to read and follow the warnings
outlined on the label pictured below.
!
DANGER: Burns from Hot Water and
Steam - Use extreme care when opening relief
valves, charging closed loop, and filling storage
tank.
The electrical element booster thermostat has
been factory set at 50°C (120°F) to reduce the
risk of scald injury. Adjusting the thermostat to a
higher setting is not recommended. Hotter water
increases the potential for Hot Water Scalds.
R
E
S
E
T
R
E
S
E
T
TURN OFF
PO WER
BEFORE
SE RV ICING
90°F150°F
125°F
(66°C)
(52°C)
(32°C)
Reset button
Thermostat
protective
cover
Thermostat
dial pointer
IMPORTANT SAFETY INFORMATION.
READ ALL INSTRUCTIONS BEFORE USING.

P.2
!
WARNING!
For your safety, the information in this manual must be followed to minimize the risk
of fire or explosion, electric shock, or to prevent property damage, personal injury, or loss
of life.
FOR INSTALLATIONS IN THE STATE OF CALIFORNIA
California Law requires that residential water heaters must be braced, anchored or
strapped to resist falling or horizontal displacement due to earthquake motions. For
residential water heaters up to 52 gallon capacity, a brochure with generic earthquake
bracing instructions can be obtained from: Office of the State Architect, 1102 Q Street,
Suite 5100, Sacramento, CA 95814 or you may call 916-445-8100 or ask a water heater
dealer.
However, applicable local codes shall govern installation. For residential water heaters
of a capacity greater than 52 gallons, consult the local building jurisdiction for acceptable
bracing procedures.
Have the installer show you the location of the circuit breaker and how to shut it off if
necessary. Turn off the circuit breaker if the water heater has been subjected to overheating,
fire, flood, physical damage or if the ECO fails to shut off.
Read this manual entirely before installing
or operating the water heater.
Be sure your appliance is properly installed
in accordance with local codes and the
provided installation instructions.
SAFETY PRECAUTIONS
Use this appliance only for its intended
purpose as described in this Installation,
Operations and Maintenance Manual
Be sure to read and understand the entire Installation, Operation and Maintenance
Manual before attempting to install or operate this water heater. It may save you time
and cost. Pay particular attention to the Safety Instructions. Failure to follow these
warnings could result in serious bodily injury or death. Should you have problems
understanding the instructions in this manual, or have any questions, STOP, and get
help from a qualified service technician, or the local utility.
Do not attempt to repair or replace any part
of your water heater unless it is specifically
recommended in this manual. All other
servicing should be referred to your install-
ing contractor or local SunEarth Distributor.
IMPORTANT SAFETY INFORMATION.
READ ALL INSTRUCTIONS BEFORE USING.
READ AND FOLLOW THIS SAFETY INFORMATION
CAREFULLY.
SAVE THESE INSTRUCTIONS

PREFACE
Let us first offer two words of grateful apprecia-
tion. Thank You! We sincerely appreciate your
business. SunEarth also wishes to say thank
you for “going solar”. Solar water heating sys-
tems help to reduce our nation’s dependence on
polluting fossil fuels, minimize the greenhouse
gas emissions associated with conventional
water heating and, very importantly, lower your
monthly utility costs.
Established in 1978, SunEarth is a leading U.S.
solar equipment manufacturer. Our products
include industry standard Empire, SunBelt,
Imperial and ThermoRay solar water heating
collectors, CopperHeart integral collector stor-
age systems, SunSiphon packaged thermosi-
phon systems, SunBurst all copper absorber
plates, SolarStrut and RexRack mounting hard-
ware. We also build specialty collectors for
unique architectural and building applications.
SunEarth SRCC OG-300 certified solar water
heating systems are sold by leading solar,
plumbing and building contractors throughout
the United States.
Your SolaRay 2 solar water heating system has
been designed to meet exacting SRCC OG-300
certification requirements. The components
found in your system have been selected by
your installation contractor for their proven
reliability, longevity and performance in your
specific region of the country.
SunEarth maintains a policy of continuous
review and improvement to ensure that SolaRay
2 systems incorporate any appropriate tech-
nological advances. To ensure that products
represent the current state of the art in solar
water heating SolaRay 2 systems are subject
to change without notice. Please consult the
SunEarth website at www.sunearthinc.com for
current information and latest manual revisions.
1) INTRODUCTION
Solar water heating systems are climate and
site specific appliances. Different types of
solar systems are installed around the world
in accordance with regional weather and water
quality conditions. System performance varies
as a function of the household hot water load,
including daily showers, laundry and kitchen
uses, average ground water and ambient air
temperatures, the home’s roof pitch and ori-
entation, and, of course, the seasonal intensity
of solar radiation. These variables, some of
which change from home to home on the same
neighborhood street, will determine how much
energy and money your SolaRay 2 system will
save on an annual basis.
Your SolaRay 2 solar system is known as a
“forced circulation” system because it utilizes
a mechanical pump to efficiently circulate the
propylene glycol heat transfer fluid (HTF)
throughout the system. The HTF protects the
collector piping from freezing and inhibits scal-
ing deposits that can reduce performance in
“open-loop” systems utilizing potable water as
the HTF. Proper application and maintenance
of the HTF can protect your SolaRay 2 solar
water heating system to minus 60° Fahrenheit.
This manual is intended as a basic solar water
heating primer. Our goal is to familiarize you
with the proper installation, operation, and
maintenance of your SolaRay 2 solar system.
This system is required to be installed by prop-
erly licensed solar or plumbing contractors in
accordance with SRCC Standard OG-300 and
all applicable national, state and local codes,
ordinances and regulations governing solar
water heating installations, as well as good
trade practices. Failure to follow the proce-
dures and practices described in this manual
may void the manufacturer’s warranty for spe-
cific component parts.
This manual covers installations utilizing one
or two SunEarth solar collectors with a single
solar storage tank and also two tank systems
that include a solar storage tank and supple-
mental tank type or tankless water heater.
For simplicity, the singular form will be used
throughout this manual when referring to all
of these components and system permutations.
Frequent reference is made throughout this
P.3

manual to specific component parts. The place-
ment of each component can be seen in system
schematic Figures 15a to 17b . A description
of each component and its function is found in
Section 10.
2) SYSTEM DESCRIPTION AND
OPERATIONAL PRINCIPLE
The key components in the SolaRay 2 solar
water heating system include the SunEarth solar
collector, solar storage tank with integral heat
exchanger, circulation pump, differential tem-
perature controller, expansion tank, pressure
gauge, mixing valve and the non-toxic propyl-
ene glycol heat transfer fluid (HTF).
The SunEarth solar collector is the heart of the
SolaRay 2 system. Simply stated, when the
sun is shining, heat energy is absorbed by the
solar collector’s absorber plate and transferred
to the HTF circulating through the solar col-
lector. The system pump efficiently circulates
this heated fluid through the collector piping
and integral tank heat exchanger. The heat
exchanger consists of coiled tubing internal
to the solar storage tank. As the HTF passes
through the heat exchanger the heat in the fluid
is transferred by conduction to the potable water
in your solar storage tank. This process is con-
tinuously repeated during the average sunny
day as the temperature in your solar storage
tank rises.
The differential temperature controller is the
brain of the system. The controller uses tem-
perature sensors to constantly monitor the tem-
peratures at the collector and at the tank. The
controller automatically turns the pump on
when useful heat is available at the collector
and turns the pump off when there is insuffi-
cient solar heat available or the tank has reached
maximum temperature.
Both single and double tank SolaRay 2 systems
are designed to provide two modes of operation.
The system will, (1) serve as a preheater to your
solar storage tank or back-up water heater, or
(2) bypass the solar collector and run 100% on
utility energy or conventional fuel. The instal-
P.4
fig. 1 COLLECTOR ORIENTATION

P.5
lation of an optional water heater time switch
allows you to control both the frequency and
duration of supplemental electric resistance
water heating. Supplemental electric heat may
not be required for much of the year depending
upon your specific requirements, thus providing
an effective third mode of operation – 100%
solar.
Section 6 provides instructions for setting the
system for automatic operation in each of these
two modes.
The propylene glycol HTF protects your SolaRay
2 solar system against freezing. SunEarth sug-
gests Dowfrost HD which can provide reliable
freeze protection at temperatures as low as
minus 60° Fahrenheit if properly applied and
maintained.
Use of uninhibited propylene glycol, ethylene
glycol, plain water or any mixture of these
fluids as the HTF in this system is strictly pro-
hibited.
Propylene glycol can degrade over time. The
process of degradation is accelerated in presence
of oxygen and/or heat. We strongly encourage
you to establish a preventative maintenance
schedule with your installation contractor. The
HTF pH level must be maintained between 8
and 10 in order to prevent glycol oxidation and
corrosion of the collector piping. SunEarth’s
collector warranty specifically excludes freeze
damage for any reason and absorber plate dam-
age resulting from the oxidation of the propyl-
ene glycol HTF.
In order to completely protect the integrity of
the solar collector and piping, the system is
designed to be drained manually if subject to
extended periods of disuse or persistent hard
freeze conditions below minus 60° Fahrenheit.
(See Sections 8.1 and 8.2)
3) INSTALLATION
REQUIREMENTS - GENERAL
3.1 Permits:
The contractor shall obtain all required permits
and approvals.
3.2 Codes, Ordinances and Standards:
The installation shall conform to all federal,
state and local regulations, codes, ordinances
and standards governing the installation of solar
water heating systems. The contractor shall
adhere to sound building safety and trade prac-
tices. Special consideration must be given to
building code requirements for roof loading and
the penetration of structural members as well as
fire rated assemblies.
3.3 Shading Considerations:
The collectors must be located in an area of the
roof that will not be shaded for the majority
of the day all year round. Adjacent buildings
and trees should be checked for possible winter
shading. The collector should not be shaded by
any permanent obstacle between 9:00 a.m. and
3:00 p.m. on any day of the year. An instru-
ment such as the Solar Pathfinder can be used
for solar site analysis.
3.4 Roof and Site Inspection:
Before the installation, the contractor shall
fig. 3
SIDE PITCH MOUNTING

inspect the condition of the roof and notify the
homeowner of any existing roof damage or nec-
essary repairs.
3.5 Structural Considerations:
The collectors must be located in a structur-
ally sound area of the roof. Penetrations into
structural members must not compromise the
structural properties of the member.
ENSURE THAT ALL STRUCTURAL
MEMBER PENETRATIONS COMPLY
WITH APPLICABLE CODES.
The collector mounting method must be capable
of maintaining the required tilt and azimuth of
the collector under the expected dead loads,
wind loads and snow loads for the location.
3.6 Building Envelope:
Penetrations through the building envelope
(including roof, walls or floor penetrations)
must not impair the enclosure function and must
meet applicable codes and best practices.
Roof penetrations whether for structural mounts
or pipe penetrations must be sealed and leak
proofed as per applicable codes and National
Roofing Contractors Association practices.
Building penetrations must not allow vermin
intrusion.
3.7 Fire-Rated Assemblies:
Penetrations through fire-rated components
must not reduce the fire resistance of the assem-
bly below code.
3.8 Building Materials:
Building materials adjacent to solar components
must not be exposed to elevated temperatures.
3.9 Confirmation of Installation Site:
The homeowner and contractor shall confirm
the location of all roof and ground mounted
components in advance of the installation.
3.10 Fluid Identity and Toxicity:
The SolaRay 2 system uses a mixture of water
and non-toxic buffered propylene glycol based
heat transfer fluid, this is heated in the collec-
P.6
fig. 4
REVERSE PITCH MOUNTING

P.7
tor and indirectly heats the domestic hot water
through the integral heat exchanger in the solar
tank. Use of toxic heat transfer fluids is pro-
hibited.
3.11 Maintenance and Servicing
When installing the system, make sure that
all the components are accessible and easy to
reach. Provide for clear access to the storage
tank, pump, expansion tank, mixing valve and
other key components. If a component in the
potable water side of the system may require
future service or maintenance make the con-
nections with brass unions or other approved
methods.
4) INSTALLATION
REQUIREMENTS - SPECIFIC
4.1 Collector Orientation
The performance of solar water heating systems
in the Northern Hemisphere is optimized when
the collector is mounted facing True South.
Performance, however, suffers very little when
the collector is oriented no more than 45° East
or West of True South. The collector should not
be shaded by any permanent obstacle between
9:00 a.m. and 3:00 p.m. on any day of the year.
4.2 Collector Tilt
Optimal annual efficiency is achieved by tilt-
ing the solar collector at an angle that equals
your latitude plus an additional 10°. This tilt
angle favors the lower winter sun when collec-
tor performance is at its lowest and minimizes
overheating during the hottest summer months.
To ensure proper water drainage from the glaz-
ing the collector must be sloped from horizon-
tal. Never mount the collector parallel to a flat
roof. Use SunEarth RexRack, Landscape Rack
or Universal tilt mount kit products to raise the
unit to the proper angle. The minimum accept-
able tilt angle from horizontal is 10°.
The solar collectors in a two collector staggered
mount installation must be spaced far enough
apart to prevent winter shading when the sun is
at its lowest angle on the winter solstice.
P.7
20% OF COLLECTOR
LENGTH
P
COLLECTOR
COMPOSITION SHINGLES
ROOF DECKING
ROOF RAFTER
COLLECTOR
C-SSN
SOLAR STRUT
COMPOSITION SHINGLES
ROOF DECKING
ROOF RAFTER
FLUSH MOUNT FOOT
FLASHING
STAINLESS STEEL LAG BOLTS
STRUT ON FOOT MOUNT FOR
COMPOSITION ROOF fig. 5

4.3 Basic Mounting Procedures
The SunEarth solar collector in your SolaRay 2
solar system may be mounted in either a vertical
or horizontal orientation on the roof (See Figure
1). Although the collector is protected from
freeze conditions by the propylene glycol HTF
and does not normally need to be drained, it is
still important to slope the collectors slightly to
allow for complete drainage if necessary. The
recommended slope is ¼” per foot of collector
horizontal run.
The collector should be mounted as close to the
storage tank as possible to minimize heat loss
in the piping runs. If the home has attic access,
mounting the collectors near the roof peak pro-
vides for additional attic workspace.
The solar collector should be mounted on the
roof in accordance with these general principles:
4.3.1 The most important structural consider-
ation is to securely anchor the solar collector
and the SunEarth mounting hardware to the
structural members of the roof with stainless
steel hanger bolts, lag bolts, standoff mounts or
other approved roof attachment methods. The
solar collector shall be attached to the mounting
hardware as detailed in Figures 5–10. (Note:
The drawings in this manual detail mounting
hardware for the SunEarth Empire, Imperial,
SunBelt and ThermoRay series collectors).
4.3.2 The collector should be raised from the
roof surface to allow for rainwater and debris to
pass under the collectors and for proper ventila-
tion of the roofing material. There should be at
least 1 ½” of clearance between the roof surface
and the bottom of the solar collectors. Local
codes may require greater clearance for snow
shedding, etc.
4.3.3 When selecting mounting hardware and
fasteners it is extremely important to avoid gal-
vanic corrosion resulting from the direct contact
of incompatible metals. Use of SunEarth anod-
ized aluminum SolarStrut mounting hardware
and stainless steel lag or hanger bolts, and fas-
tening hardware is recommended. In climates
subject to severe winters or high humidity use
of galvanized fasteners is prohibited.
P.8
20% OF COLLECTOR
LENGTH
COLLECTOR
ROOF RAFTER
ROOF DECKING
COMPOSITE SHINGLES
COLLECTOR
C-SSN
ROOF RAFTER
ROOF DECKING
COMPOSITION SHINGLES
SOLAR STRUT
STAINLESS STEEL LAG BOLT
STANDOFF
LEAD FLASHING
FILL VOID WITH SEALANT
fig. 6
STRUT ON STANDOFF FOR
COMPOSITION SHINGLE ROOF

4.3.4 Preserving the integrity of the roof mem-
brane is the most important roofing consider-
ation. Ensure that all roof penetrations required
to plumb and mount the solar collector are
properly flashed and sealed in accordance with
standard roofing practices and in compliance
with all local codes and ordinances.
4.3.5 If the region is subject to hurricane con-
ditions, additional steps may be required to
secure the collector and mounting hardware to
the structural members. In certain areas of the
country, local building codes may require col-
lector wind load testing or prescribe specific
mounting procedures. Consult your local build-
ing department regarding any special consider-
ations in your area.
4.4 Collector Loop Plumbing
The collector loop must be plumbed using cop-
per or stainless steel piping and copper, brass,
bronze or stainless steel fittings. Lead-free
solder shall be used. Use of galvanized steel,
CPVC, PVC, PEX or any other type of plastic
pipe is prohibited. The collectors can produce
temperatures that will melt plastic piping.
The collector loop pipe sizing must be ade-
quately sized to handle the design flow rates
for the collector(s). SunEarth recommends ½”
nominal diameter pipe sizes for single collec-
tor systems and ¾” nominal diameter pipe for
two collector systems. It may be necessary to
increase the pipe size for longer pipe runs or
reduce the pipe size for shorter runs or higher
efficiency pumps. The pipe must be large
enough that the velocity of the HTF does not
exceed 4 ft/s. Hot HTF flowing at over 4 ft/s
in a pipe will erode the pipe and reduce system
life. When more than one collector is used in
the system, the collectors should be plumbed in
a reverse return piping arrangement in order to
maintain equal flow through all collectors in the
array. Where reverse return piping is not pos-
sible flow balancing valves must be installed to
ensure that the difference in flow rates between
collectors is no more than +/- 10%.
Piping in new solar installations can be covered
with dirt, grease, solder flux or other impurities
that over time affect the quality of the propylene
P.9
20% OF COLLECTOR
LENGTH
T
COLLECTOR
ROOF RAFTER
ROOF DECKING
BARREL TILE
COLLECTOR C-SSN
SOLAR STRUT
BARREL TILE
ROOF DECKING
ROOF RAFTER
STANDOFF
BASE FLASHING
LAG BOLTS
FLEXIBLE TILE FLASHING
STRUT ON STANDOFF FOR
CURVED TILE ROOF fig. 7

P.10
glycol HTF. A thorough cleaning is required
before charging the system with propylene gly-
col. Carefully review the cleaning procedures in
“Charging the System” outlined in section 4.14.
All vertical piping between the storage tank
and the collector shall be supported at each
story or at maximum intervals of ten feet (10’).
Horizontal pipe runs should be supported to
allow complete drainage of the system if nec-
essary, the recommended slope is ¼” per foot
sloped to drain.
Horizontal roof runs shall be secured and sup-
ported providing at least 1 ½ inches clearance
from the roof. Standard best piping practices
shall be followed as described in the Uniform
Plumbing Code, International Plumbing Code
or other recognized code or standard. Plumbers
tape or tube strap is required. The pipe insula-
tion should not be compressed or crimped by
the strapping material.
Only Solder Fluxes meeting the criteria of
ASTM B 813 should be utilized for joining by
soldering any copper and copper alloy tube and
fittings in the entire solar system.
Allowance should be made for expansion and
contraction of piping due to changes in tem-
perature of the HTF and piping. Use flexible
pipe supports and avoid long straight piping
runs. Soft copper coils or other flexible piping
is recommended, if hard copper is used include
bends and elbows to allow for expansion such
as swing joints at the collector inlet & outlet.
The installation of all horizontal and vertical
piping shall not reduce the performance or
rating of any structural member or fire rated
assembly. Adhere to all applicable local codes
and ordinances.
4.5 Pipe Insulation
WARNING: HOT PIPES MAY CAUSE
BURNS IF TOUCHED. ENSURE THAT
ALL PIPES AND FITTINGS ACCESSIBLE
TO THE PUBLIC ARE WELL INSULATED.
COMPONENTS ACCESSIBLE TO PUBLIC
TRAFFIC MUST BE KEPT BELOW 140ºF
OR CLEARLY LABELLED WITH AN
APPROPRIATE WARNING.
20% OF COLLECTOR
LENGTH
COLLECTOR
ROOF RAFTER
ROOF DECKING
FLAT TILE
COLLECTOR
C-SSN
SOLAR STRUT
FLAT TILE
ROOF DECKING
ROOF RAFTER
STANDOFF
FLASHING
LAG BOLTS
STRUT ON STAND OFF FOR FLAT
TILE ROOF fig. 8

The collector loop piping, plus any intercon-
necting hot water piping shall be well insulated
with a high quality flexible closed cell insula-
tion to minimize heat loss. The insulation shall
have a maximum operating temperature of
220°F or higher. The wall thickness of the pipe
insulation should not be less than ½”. A 1” wall
thickness is required in all areas prone to annual
hard freeze conditions. When it comes to pipe
insulation the rule is simple: thicker is better.
To the extent possible, slide the insulation mate-
rial over the pipe without cutting or taping. All
butt joints must be sealed with contact adhesive.
The use of rigid polyethylene pipe insulation is
prohibited. The temperatures generated by your
collector in the summer months or under stag-
nation conditions can melt this type of material.
Any above ground exterior pipe insulation is
subject to UV degradation and must be jacket-
ed, wrapped with aluminum foil tape, or painted
with two coats of high quality water-based
acrylic resin coating as supplied by the insula-
tion manufacturer.
4.6 Control System
4.6.1 Differential Controller
The differential controller must be installed in
an accessible location so that the user inter-
face, typically an LCD screen, can be seen.
Switches on the controller must be labeled and
accessible. Always follow the controller manu-
facturers wiring instructions when installing
differential controllers. Control system inputs;
such as signals from temperature sensors or
flow meters shall be connected to the appropri-
ate low voltage terminals. Controller output to
the pump will be medium voltage, 110 VAC or
220 VAC. Medium voltage power to the pump
may be supplied by a line cord from the pump
to an outlet in the controller or hard wired from
the controller medium voltage terminals to the
pump. Wiring must comply with standard elec-
trical practice and all applicable electrical codes
for the jurisdiction having authority, this may
require the use of conduit for medium voltage
wiring.
The differential controller must have a provi-
sion to manually turn the pump on and off
(manual override) so that pump operation can
be checked at any time and the pump can be
manually stopped if required for maintenance
or troubleshooting purposes.
Set the maximum tank temperature to the
desired maximum temperature, this tempera-
ture must be lower than the rated maximum
temperature of the tank and associated compo-
nents. When the solar loop heats the tank to this
temperature, the pump will shut off preventing
further heat gains to the solar tank.
4.6.2 Collector Sensor Placement
The collector sensor shall be located on the
solar loop return line as close to the collector
as possible. Sensors are typically accurate to
+/- ½°F if properly installed and weatherized.
The collector probe sensor shall be attached to
the SunEarth collector header pipe either with
a stainless steel hose clamp or by inserting the
probe sensor into a thermal well in contact with
the fluid near the outlet header pipe.
It is recommended that the connection between
the silicon sensor lead and low voltage sensor
wiring be made inside the attic, a NEMA 4X
junction box or some other indoor space. When
using wire nuts to make the connection, the
crimped brass cap on the end of the sensor wire
should be removed and the wire striped before
inserting into the wire nut. Where connections
from the sensor lead to the low voltage wiring
is made at an exposed location the connection
should be by crimp and heat shrink or solder
and heat shrink butt connections. Wire nuts or
screw connectors should not be used in exposed
locations due to the likelihood of corrosion
which will result in a compromised electrical
connection.
Thoroughly wrap and weatherize the insulation
with electrician’s tape or insulation tape as pro-
vided by the manufacturer. See Figure 12 for
collector sensor installation detail.
P.11

P.12
If an electrical potential exists between the roof
and ground, this may induce current in the col-
lector sensor wire. This current will result in
a false signal being received by the controller
and hence incorrect temperature readings. To
prevent such current the copper plate and pip-
ing should be independently grounded. This
will provide a separate path to ground from the
roof which does not interfere with the sensor
readings.
Grounding can be achieved by running a sepa-
rate ground wire to the collectors or ensur-
ing that the copper pipe in the closed loop is
grounded and there are no electrical disconti-
nuities between the grounding point and the
collector. Grounding of the collector & roof
piping is especially important in locations that
often experience electrical storms and electrical
atmospheric activity.
4.6.3 Low Voltage Wiring
The low voltage wiring used to connect the sen-
sor lead to the controller shall be a minimum18
AWG. The wiring should be bare or tinned cop-
per, two conductor, stranded, PVC insulated,
with a PVC UV rated jacket suitable for exterior
use. In locations that often experience electrical
storms and electrical atmospheric activity the
low voltage sensor wire should also be shielded
and the shielding connected to ground.
A
REAR LEG
FOOT
SUPPORT STRUT
DETAIL A
COLLECTOR
MOUNTING
CHANNEL
C-SSN
FOOT
LANDSCAPE RACK
fig. 10

P.13
Low voltage wire shall be rated for the full
range of temperatures expected in the location,
typically wire is rated up to 160°F. The low
voltage sensor wire must not be in direct contact
with the pipe as the wire insulation may melt
when in contact with a hot pipe. Low voltage
sensor wire must be run OUTSIDE the pipe
insulation. Where the low voltage wire is run in
an exposed location, it should be run OUTSIDE
the pipe insulation but UNDER the insulation
jacket or wrap to protect the wire from UV
exposure.
4.7 Installing the Solar Tank
The solar tank is heated indirectly through a
coiled heat exchanger that is integral to the tank.
The heat exchanger is immersed in the solar
storage tank.
In plumbing the solar storage tank and expan-
sion tank make sure that all the components are
accessible and easy to reach. Provide for clear
access to the storage tank, pump, expansion
tank, mixing valve and other key components.
If a component in the potable water side of the
system may require future service or mainte-
nance make the connections with brass unions
or other approved methods. Use only brass,
copper and stainless steel fittings in plumbing
the solar storage tank and expansion tank. The
use of galvanized fittings, CPVC, PVC or other
REXRACK
(FOR MULTIPLE COLLECTORS WITH PORTRAIT TILT)
fig. 11

plastic pipe is prohibited. Di-electric nipples
may be required by the (Authority Having
Jurisdiction) AHJ on the potable side.
Hard copper connections to the city cold water
supply line and the home hot water feed lines
are recommended. The gaskets in standard
water heater flex hose connectors can become
brittle and compressed over time and begin
leaking on the water heater. If not detected in
a timely manner even a small drip or leak may
cause serious damage to the tank’s electrical
components or, in extreme cases, may cause the
tank to leak from the outside in.
Tank plumbing is required to provide for the
isolation of the solar storage tank from the city
cold water supply line by means of an isolat-
ing ball valve (COMPONENT #23, FIGURES
15A; 15B; 16A; 16B; 17A; 17B ).
The differential temperature controller shall
have a screen readout to show temperatures of
the collector and storage tank. Otherwise, line
thermometers shall be installed in the collector
supply and return lines to allow for a simple
diagnostic check of proper system operation.
On a sunny day the hot water return line should
be approximately 5°F – 12°F warmer than the
water in the collector supply line. Compare the
temperature readings in the two line thermom-
eters (COMPONENT #3, FIGURES 15A; 15B;
16A; 16B; 17A; 17B).
A high quality thermostatic mixing valve is a
required component in all OG-300 certified sys-
P.14
Hot Water
Return Line
Sensor Wire Must NOT Be
Placed In Direct Contact
With Pipe
Crimp Or Solder Connection
- Use Heat Shrink If In
Exposed Location
Silicon Sensor Lead May Be
In Contact With Pipe
Sensor Clamped to Collector
Header Pipe & Covered With
Insulation
Protective
Insulation Jacket or
Approved Coating
COLLECTOR SENSOR fig. 12

tems and should be plumbed in line with brass
union connections for ease of future repair or
replacement (COMPONENT #32, FIGURES
15A; 15B; 16A; 16B; 17A; 17B ). The mixing
valve shall be standard ASSE 1017 approved.
The temperatures generated by your SolaRay
2 system will vary throughout the year. In the
Northern Hemisphere the water temperature
will be hottest in the spring and summer months
while cooler temperatures are to be expected
from November through March. On sunny days
the end of day solar tank temperatures may
range between 110ºF to 180ºF depending upon
the season and hot water demand. The mixing
valve refrenced above blends the hot and cold
water supplies to deliver hot water to your fix-
tures at a safe, controlled temperature.
WARNING: SCALDING CAN OCCUR
WITHIN FIVE SECONDS WHEN WATER
TEMPERATURESAPPROACH140ºF.THE
MIXING VALVE SHALL BE ADJUSTED
BY YOUR CONTRACTOR TO PROVIDE
WATER TO YOUR FIXTURES AT NO
MORE THAN 122ºF.
The ¾” cold water supply line to the solar stor-
age tank shall be insulated with minimum
7
/8” X
½” pipe insulation to a minimum distance of 5’
behind the storage tank, or to the wall if closer
than 5’.
4.8 Tank Sensor Placement
Figure 18 details the proper placement of the
solar storage tank sensor. Tank sensor shall
have good thermal contact with the tank wall in
order to accurately measure the temperature of
the water at the bottom of the tank. It is recom-
mended that the sensor be installed in a brass
or copper thermalwell screwed into the lower
sensor port in the tank.
Thoroughly weatherize the wire connections in
accordance with section 4.6.2.
4.9 Tank Insulation
SunEarth heat exchanger tanks have an insula-
tion value of approximately R-17.3.
Conventional back-up electric water heaters
have insulation values between R-12 and R-20.
The R value expresses the thermal resistance of
the tank insulation. The higher the “R-value”
value the more effective the insulation material
is at preventing heat loss. The use of any solar
storage tank with and R value below R12 is
prohibited.
The storage tank should not be placed directly
on an uninsulated floor or concrete slab. In
order to prevent moisture damage to the base of
the tanks and reduce heat loss to the floor slab,
the tank should be raised off the floor on a pad.
4.10 Expansion Tank
The collector loop expansion tank shall be rated
for propylene glycol based HTF and rated to
operate up to 180ºF and at a pressure not less
than the discharge pressure setting of the pres-
sure relief valve in the collector loop.
The collector loop expansion tank should be
sized so that the acceptance volume of the
expansion tank exceeds the volume of fluid in
the collector(s); this will allow the entire con-
tents of the collectors to boil without resulting
in the pressure relief valve discharging (this is
sometimes referred to as a “steam back” sys-
tem). If the system design prevents the HTF
from boiling, even during conditions with no
hot water load, the expansion tank may be
sized for liquid expansion only (non-boiling
systems). When the stagnation temperature* of
the collector(s) is lower than the boiling point
of the HTF (at the initial charge pressure of the
system) the system design will prevent the HTF
from boiling and therefore a smaller expansion
tank (sized for liquid expansion only) may be
used for these systems (this design methodolo-
gy is referred to as “low stagnation protection”).
WARNING: WHEN USING THE LOW
STAGNATION PROTECTION METHOD
THE HTF MUST BE RATED TO OPERATE
AT TEMPERATURES ABOVE THE
STAGNATION TEMPERATURE* OF THE
COLLECTORS.
P.15

* 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