Mixing Valves; Circulation Pumps - Polaris PG10/GHX Instruction Manual

or electrical line noise such as EMI (electro magnetic interference)
or RFI (radio frequency interference) may cause erratic control
system operation and malfunction.
A high quality power supply filter/suppressor must be installed
if the above conditions exist. Call the technical support phone
number for more information.
NOTE: Malfunctions caused by the power supply and the costs
to install the power supply filters are not covered under the
limited warranty.

MIXING VALVES

Water temperature over 125°F (52°C)
can cause severe burns instantly
resulting in severe injury or death.
Children, the elderly and the
physically or mentally disabled are at
highest risk for scald injury.
Feel water before bathing or
showering.
Temperature limiting devices such as
mixing valves must be installed
when required by codes and to
ensure safe temperatures at fixtures.
Water heated to a temperature which will satisfy clothes washing,
dish washing, and other sanitizing needs can scald and cause
permanent injury upon contact. Short repeated heating cycles
caused by small hot water uses can cause temperatures at the point
of use to exceed the water heater's temperature setting by up to
20°F (11°C).
Some people are more likely to be permanently injured by hot water
than others. These include the elderly, children, the infirm and the
physically/mentally disabled. Table 3 shows the approximate time-
to-burn relationship for normal adult skin. If anyone using hot water
provided by the water heater being installed fits into one of these
groups or if there is a local code or state law requiring a certain water
temperature at the point of use, then special precautions must be taken.
In addition to using the lowest possible temperature setting that
satisfies the demand of the application a Mixing Valve should be
installed at the water heater or at the hot water taps to further
reduce system water temperature. See Figure 7 below and Figures
51 through 53 in Piping Diagrams beginning on Page 58.
TEMPERED WATER
COLD
WATER
INLET
Mixing valves are available at plumbing supply stores. Consult a
Qualified Installer or Service Agency. Follow mixing valve manufacturer's
instructions for installation of the valves.
In all cases, the following burn table must be used.
Water Temperature Time for 1st Degree Burn
°F (°C)
110 (43.3) (normal shower temp.)
116 (46.7)
116 (46.7)
122 (50)
131 (55)
140 (60)
149 (65)
154 (67.8)
(U.S. Government Memorandum, C.P.S.C., Peter L. Armstrong, Sept. 15, 1978)

CIRCULATION PUMPS

A circulating pump is used when a system requires a circulating loop or
there is a storage tank used in conjunction with the water heater. The
tank is provided with a 1" NPT recirculation loop return connection. See
the Piping Diagrams section beginning on Page 58 for the installation
location of circulating pumps.
See Circulation Pump Wiring Diagrams on page 57 for electrical hookup
information. Install in accordance with the current edition of the National
Electrical Code, NFPA 70.
Refer to the circulating pump manufacturer's instructions for its operation,
lubrication and maintenance instructions.
17
HOT WATER
OUTLET
12" TO 15"
(30-38 cm)
OUTLET
CHECK
VALVE
MIXING
CHECK
VALVE
VALVE
TO TANK
INLET
Figure 7
Table 3
Time for Permanent
(Less Severe Burns) 2nd & 3rd Degree
(Most Severe Burns)
(pain threshold)
35 minutes 45 minutes
1 minute 5 minutes
5 seconds 25 seconds
2 seconds 5 seconds
1 second 2 seconds
instantaneous 1 second
Burns