HTP Drain Back, Установка, Запуск, Обслуживание, Запчасти, Гарантия

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lp-585 Rev. 000 Rel. 001 Date 9.10.18
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Part 6 - Fluid Quality
A. Solar Loop Fluid Quality
HTP, Inc. recommends the use of potable water as HTF in its drain
back solar systems.
Fluid in direct flow through the solar collectors must first meet
potable water requirements; any fluid circulated through the
collectors should be non-corrosive to copper. In addition, water
quality must meet the following requirements listed below.
Total Dissolved Solids
< 500 ppm
Total Hardness < 7 grains (120 ppm)
Chloride < 100 ppm
pH Levels 6.5 - 8.5
In order to meet health and safety regulations, solar system antifreeze
fluid should be food grade polypropylene glycol, FDA rated as
“generally recognized as safe” (GRAS). Using proper concentrations
of glycol, solar systems can be operated at ambient temperatures as
low as -60
o
F. Freeze tolerance limits are based upon an assumed set
of environmental conditions. Refer to the DOWFROST specification
sheet in the back of this manual for recommended concentrations.
If using a glycol / potable water mix, the water must meet the
above requirements, and the glycol content of the liquid must
not exceed 50%, unless the manufacture specifies that a different
ratio is recommended for use with solar water heaters. Glycol may
need to be changed periodically (every 3-5 years) to prevent it from
becoming acidic; please refer to the guidelines provided by the
glycol manufacturer regarding replacement.
B. Fluid Safety Labeling
Included with your solar system is a set of labels which describe
component function. These labels alert the owner to potential
hazards. Affix these labels by string/wire/tie on valves, and/or “peel
and stick” on pipe insulation. Labels on the solar loop system must
contain the following warning:
“No other fluid shall be used that would change the original
classification of the system. Unauthorized alterations to this system
could result in a hazardous health condition.” All labeling MUST be
in place at final inspection.
C. Freeze Protection
Though drain back systems provide freeze protection for the solar
collectors, additional care must be taken in regions that experience
freezing conditions at any time throughout the year.
“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 the Supplier’s
instructions if the air temperature is expected to approach the
specified freeze tolerance limit.”
For areas with temperatures not falling below –5
o
C/23
o
F, a simple
low temperature controller may be used to guard against freezing. If
necessary, backup freeze protection in the form of an uninterrupted
power supply (UPS), or freeze valves (which open to allow water to
dribble out) should also be installed.
For areas with temperatures that fall below –5
o
C /23
o
F, a closed
loop filled with a polypropylene glycol-water mix should be used to
provide hard freeze protection. Please refer to glycol manufacturer’s
specifications about the temperature ranges the liquid can
withstand. Only food grade polypropylene-glycol, FDA rated as
GRAS, should be used.
NOTE: HTP DOES NOT WARRANT THE SOLAR WATER HEATER, SOLAR
COLLECTOR, OR ANY COMPONENTS AGAINST FREEZE RELATED
DAMAGE.
Part 7 - Start-Up Preparation
DO NOT MOVE ON TO THESE STEPS UNTIL THE ENTIRE SOLAR
SYSTEM, INCLUDING ALL PIPING, SOLAR COLLECTORS, SENSORS,
PUMP, CONTROLS, AND ELECTRICAL CONNECTIONS, ARE PROPERLY
SECURED, INSULATED, LABELED AND INSTALLED.
A. Check for Leaks in the Solar Loop
To check for leaks in the solar loop, utilize the same procedure used by
plumbers checking for leaks in new construction.
1. Isolate the solar loop.
2. Use a compressor to pressurize the solar loop to 25 PSI.
3. After 1 hour, check to see if there has been a drop in pressure.
a. If pressure has not dropped, slowly release the remaining air
pressure in the loop and move on to Section B.
b. If pressure has dropped, use a spray bottle with soapy water
to locate the leak. Once all leaks have been found and repaired,
pressurize the solar loop again.
NOTE:
Do not introduce heat transfer fluid into the solar system until
you have successfully completed the pressure test.
B. Fill the Drain Back Reservoir
1. Attach hose to solar loop fill valve.
2. Open fill valve and the bleed valve on the drain back tank sight
tube (see Specification drawings for locations).
3. Slowly fill the drain back reservoir to the top of the sight tube.
4. When nearly full, close bleed valve and add between 2 and
5 PSI head pressure to the system. When system is full and at
desired head pressure, shut off fill valve.
5. Remove fill hose.
Take care not to overfill the drain back solar system. Overfilling will
cause a potentially dangerous condition that could lead to freezing
and failure of the solar system.
C. Start-Up Procedure
Once the system is filled as prescribed above:
1. Apply power to the solar controller.
2. Set controller to operate pump manually. Let pump run for 5
minutes.
3. Check for leaks at collectors and in attic, if applicable.
4. If no leaks are found, program controller for your drain back
system (see solar controller programming instructions).
If the sun is shining and the tank is cool, the pump should turn on
and begin circulating water. Check control settings to maximize your
system performance.
Part 8 - Service / Maintenance Procedures
A properly maintained solar water heating system can provide years
of dependable, trouble-free service. It is suggested that a routine
preventive maintenance program be established and followed by the
end user with the solar contractor. Listed below is the maintenance
check list that outlines the primary components of the solar system
that need to be inspected annually.
1. HTF Glycol (if used) – It is very important that the quality of the
glycol is maintained to avoid damage to the collector loop and related
components. See the manufacturer’s data sheet for further details.
2. Water quality can affect the operation of the solar heat exchanger
over time. In very hard water areas, it is recommended to drain (#14) a
few gallons of water from the bottom of the storage tank to keep the
water heater free of sediment.