General installation information cont, Low water coil limit, Condensate drain – WaterFurnace 7 Series User Manual

Page 8: Water quality

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8

7 SERIES 50Hz 700A11 INSTALLATION MANUAL

Figure 6: Unit Pitch for Drain

Figure 5: Horizontal Drain Connection

Low Water Coil Limit

Set the freeze sensing switch SW2-1 on the Aurora Base
Control (ABC) printed circuit board for applications using
a closed loop antifreeze solution to “LOOP” (-9.4°C). On
applications using an open loop/ground water system (or
closed loop no antifreeze), set this dip switch to “WELL”
(-1.1°C), the factory default setting. (Refer to the DIP Switch
Settings table in the Aurora Control section.)

Condensate Drain

On vertical units, the internal condensate drain assembly
consists of a drain tube which is connected to the drain
pan, a 19.1mm 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 PVC stub is provided for condensate
drain piping connection. An external trap is required (see
below). If a vent is necessary, an open stand pipe may be
applied to a tee in the field-installed condensate piping.

Water Quality

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. The heat
exchanger coils in ground water systems 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. Hot water generator coils

can likewise become scaled and possibly plugged. In areas
with extremely hard water, the owner should be informed
that the heat exchanger may require occasional flushing.

Units with cupronickel heat exchangers are recommended
for open loop applications due to the increased resistance
to build-up and corrosion, along with reduced wear caused
by acid cleaning. Failure to adhere to the guidelines in the
water quality table could result in the loss of warranty.

General Installation Information cont.

Material

Copper

90/10 Cupronickel

316 Stainless Steel

pH

Acidity/Alkalinity

7 - 9

7 - 9

7 - 9

Scaling

Calcium and

Magnesium Carbonate

(Total Hardness)

less than 350 ppm

(Total Hardness)

less than 350 ppm

(Total Hardness)

less than 350 ppm

Corrosion

Hydrogen Sulfide

Less than 0.5 ppm (rotten egg

smell appears at 0.5 ppm)

10 - 50 ppm

Less than 1 ppm

Sulfates

Less than 125 ppm

Less than 125 ppm

Less than 200 ppm

Chlorine

Less than 0.5 ppm

Less than 0.5 ppm

Less than 0.5 ppm

Chlorides

Less than 20 ppm

Less than 125 ppm

Less than 300 ppm

Carbon Dioxide

Less than 50 ppm

10 - 50 ppm

10 - 50 ppm

Ammonia

Less than 2 ppm

Less than 2 ppm

Less than 20 ppm

Ammonia Chloride

Less than 0.5 ppm

Less than 0.5 ppm

Less than 0.5 ppm

Ammonia Nitrate

Less than 0.5 ppm

Less than 0.5 ppm

Less than 0.5 ppm

Ammonia Hydroxide

Less than 0.5 ppm

Less than 0.5 ppm

Less than 0.5 ppm

Ammonia Sulfate

Less than 0.5 ppm

Less than 0.5 ppm

Less than 0.5 ppm

Total Dissolved Solids (TDS)

Less than 1000 ppm

1000 - 1500 ppm

1000 - 1500 ppm

LSI Index

+0.5 to -0.5

+0.5 to -0.5

+0.5 to -0.5

Iron Fouling

(Biological Growth)

Iron, FE

2

+ (Ferrous)

Bacterial Iron Potential

< 0.2 ppm

< 0.2 ppm

< 0.2 ppm

Iron Oxide

Less than 1 ppm, above this

level deposition will occur

Less than 1 ppm, above this

level deposition will occur

Less than 1 ppm, above this

level deposition will occur

Erosion

Suspended Solids

Less than 10 ppm and filtered

for max. of 600 micron size

Less than 10 ppm and filtered

for max. of 600 micron size

Less than 10 ppm and filtered

for max. of 600 micron size

Threshold Velocity

(Fresh Water)

< 1.8 m/sec

< 1.8 m/sec

< 1.8 m/sec

NOTES: Grains = ppm divided by 17

mg/L is equivalent to ppm

2/22/12

38.1 mm

PVC tube stub

PVC coupling

Vent (if needed)

PVC tube stub

10.4 mm per meter

38.1 mm

12.7 mm Pitch

Drain

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