Mammoth 800 to 5500 CFM: Dedicated Outdoor Air System with Enthalpy Wheels (VHC) - Manual (Page 10)

MAMM-VHC-IOM-1A (JANUARY 2013) 10
Before connecting piping to the unit, the water supply line
and return line must be flushed to eliminate the foreign
material. In low temperature applications, the water supply
line and return line should be insulated to prevent con-
densate and antifreeze solution should be used to protect
water-to-refrigerant heat exchanger from freezing damage.
See submittal drawings for water piping connection loca-
tion. The concentration of water/glycol solution depends
on the field application. On open loop systems, a water
strainer (16–20 mesh minimum, 20–40 mesh best) is rec-
ommended to be installed in the water inlet line to the unit
to eliminate contaminants and it must be used for units
having water-to-refrigerant brazed plate heat exchanger.
A water flow switch is recommended to be installed in line
to prevent possible freeze-up due to loss of water flow.
An air vent must be installed on the high side of the water
line to discharge the non-condensable air in order to avoid
unexpected high head pressure and poor cooling/heating
performance. Manual shut-off valves are recommended to
be installed for the convenience of future service.
A circuit balancing valve with pressure and temperature
gauge connections is recommended to be installed in the
water line for balancing and service.
See
Appendix K for water line field mounted options and
accessories.
Water Source Heat Pump (WSHP) Water Piping and Connections
CAUTION
In areas where scaling can become serious, a periodic
cleaning for the water-to-refrigerant heat exchanger is
recommended. Standard water coil cleaning procedure
should be followed which must be done by a qualified ser-
vice mechanic.
Cooling coil drain pan is provided with a 1¼” MPT drain
connection. A drain trap and condensate line of equal size
must be field provided on the drain connection to prevent
air or sewer gases from being pulled into the unit caused
by the negative (suction) pressure and forcing water out of
the pan into the unit.
A label with recommended trap height is provided on the
unit as per Figure 3.
The trap height allows for the maximum suction pressure
after the cooling coil with intake damper, dirty pre and final
high efficiency filters, high efficiency heat wheel plus 1” w.c.
per ASHRAE guidelines for outdoor units with intake hood
or indoor unit with up to 0.5” w.c. external static intake duct.
Slope the drain lines downward in direction of flow 1/8 inch
per foot referring to local codes for proper drainage require-
ments. Installing a plug for cleaning of the trap is recom-
mended. Prime the trap by filling with water before start-up.
Winterize the drain line before freezing on outdoor units.
Check and clear drains annually at start of cooling sea-
son. Drainage problems can occur should drains be in-
active and dry out, or due to reduced water flow caused
by buildup of algae. Regular maintenance will prevent
these from occurring.
Condensate Drain Trap
6.0” [191 mm]
minimum
3.0” [76 mm]
minimum
PN 500005436
Condensate drain must be trapped as shown.
Refer to IOM for further instructions and maintenance.
Le drain de condensation doit être fabriqué et intallé tel que
le croquis ci-bas. Voir le manuel d’installation,
opération et maintenance pour instructions.
Unit baserail
Curb
Curb
support
6.578”
[167.08 mm]
3.375”
[85.73 mm]
Figure 3: Condensate drain trap label