5
SPECTRA COMMERCIAL AND RESIDENTIAL INSTALLATION GUIDE
Never use flexible hoses smaller than 1" inside diameter on the unit and limit hose
length to 10 ft. per connection. Check carefully for water leaks.
Water Quality
The unit may be ordered with either a copper or a cupronickel coaxial heat exchanger.
Copper is adequate for closed loop and open loop ground water systems which are not high
in mineral content. In conditions anticipating moderate scale formation or in brackish water,
a cupronickel heat exchanger is recommended. In ground water situations where scaling
could be heavy or where biological growth such as iron bacteria will be present, a closed
loop system is recommended. Ground water unit heat exchanger coils may over a period of
time lose heat exchange capabilities due to a buildup of mineral deposits inside. These can
be cleaned, but only by a qualified service mechanic as special solutions and pumping
equipment are required. Desuperheater coils can likewise become scaled and possibly
plugged. In areas with extremely hard water, the homeowner should be informed that the
heat exchanger may require occasional acid flushing.
Freeze Protection (Commercial Microprocessor Only)
Set the freeze protection switch SW1 #2 on the microprocessor board for applications
using a closed loop antifreeze solution to" LOOP". On applications using an open loop/
ground water system or non freeze protected loop, set to "WELL" (the factory setting).
Condensate Drain
On vertical units, the internal condensate drain assembly consists of a drain tube which
is connected to the drain pan, a 3/4" PVC female adapter and a flexible connecting hose.
The female adapter may exit either the front or the side of the cabinet. The adapter should
be glued to the field-installed PVC condensate piping. On vertical units, a condensate hose
is inside all cabinets as a trapping loop; therefore, an external trap is not necessary. On
horizontal units, a copper stub is provided for condensate drain piping connection. An
external trap is required (see Figure 3A page 4). If a vent is necessary, an open stand pipe
may be applied to a tee in the field-installed condensate piping.
Air Coil
To obtain maximum performance the air coil should be cleaned before start up. A 10%
solution of dishwasher detergent and 90% water is recommended for both sides of coil. A
thorough water rinse should follow.
Boiler/Cooling Tower
The water loop is usually maintained between 60
°
F and 90
°
F (Spectra units allow 25
°
F -
110
°
F EWT) for proper heating and cooling operation. see Figure 5 page 6 for a typical
installation.
To reject excess heat from the water loop, the use of a closed circuit evaporative cooler
or an open type cooling tower with a secondary heat exchanger between the tower and the
water loop is recommended. If an open type cooling tower is used without a secondary heat
exchanger, continuous chemical treatment and filtering of the water must be performed to
ensure the water is free from damaging materials.
CAUTION: Water piping exposed to outside temperatures may be subject to freezing.
NOTE:
For Boiler/Cooling Tower Systems with no antifreeze solution, set SW1-Switch
#4 to the "WELL" position.
Boiler/Cooling
Tower Closed
Loop Systems
