HTP FP-40SC - Manual (Page 23)

23
PART 6 – PLUMBING CONNECTIONS
A. TEMPERATURE SENSOR INSERTION
The temperature sensor well must be located near the hot out
port. If the collector is designed without a sensor well, use a
stainless steel clamp to clamp the sensor onto the hot out port
directly to the copper pipe exiting the collector. Mount the
sensor as close to the collector as possible. Ensure that the
sensor and cable used on the collector are high temperature
rated (up to 200
o
C / 395
o
F). The sensor cable should not come
in direct contact with the piping.
Ensure that any pipe insulation is watertight. Use silicone
sealant to ensure a watertight seal against the collector.
NOTE: To ensure temperature sensing accuracy, mount the sensor as close to the collector as possible.
B. HEADER CONNECTION
Never use dielectric unions or galvanized steel fittings when connecting to a stainless steel storage tank
or heater. Use only copper or brass fittings. Teflon thread sealant must be used on all connections.
Non-Galvanized Connections / Pipe Fitting: To ensure a sound seal, use plumbing thread glue or
Teflon tape approved for use in glycol based systems. Tighten using two wrenches, taking care not to
stress the copper pipe. Do not over tighten.
Brazing/Sweating/Soldering to the collector is acceptable, but not recommended, as doing so can
damage the header grommet. Care must be taken to avoid exposing the silicone rubber seal to the torch
flame. Ideally, place a wet cotton cloth against the rubber seal to prevent heat damage.
C. AIR PURGE
Once the inlet and outlet are connected to the plumbing system, the collector loop should be purged of
air.
1. OPEN LOOP
For a system without an auto-air vent, a drain valve on the supply line should be installed along with a ball
valve or a metal coin vent on the tank side. With the ball valve closed, the drain valve can be opened to
allow air to escape as water pressure forces through the line.
When opening the drain valve, released water may be hot. Steam may release as well. Failure to take
caution when opening drain valve could result in serious personal injury.
Once the drain valve no longer releases air, close it. Then open the ball valve so normal operation may
begin.
If an auto-air vent is installed on the outlet of the collector, air will automatically eliminate from the solar
line. If using a manual air vent, open it until all air is eliminated.
Figure 22: Detail of sensor cable