AAON WH Series Installation Operation & Maintenance - Warning
25
of the condenser water must be controlled.
All make-up water has minerals in it and as
the water is evaporated in the cooling tower,
these minerals remain. As the mineral
content of the water increases, the
conductivity of the water increases. A bleed-
off (drain valve) must be provided for the
condenser water loop.
Field provided and installed water treatment
program must be compatible with stainless
steel, copper, aluminum, ABS plastic, and
PVC. Batch feed processes should never be
used as concentrated chemicals can cause
corrosion. Never use hydrochloric acid
(muriatic acid) or chlorine as it will corrode
stainless steel.
Water loop piping runs through unheated
areas or outside the building should be
insulated.
NOTE: Ball valves should be installed in
the condenser water supply and return lines
for unit isolation and water flow balancing.
All manual flow valves should be of the ball
valve design. Globe or gate valves should
not be used due to high pressure drops and
poor throttling characteristics.
Pressure and temperature ports are
recommended in condenser water supply
and return lines for system balancing. These
openings should be 5 to 10 pipe diameters
from the unit water connections. To allow
for mixing and temperature stabilization,
wells in the water piping should extend at
least ½ pipe diameter into the pipe.
Piping systems should not exceed 10 ft/sec
fluid velocity to ensure tube wall integrity
and reduce noise.
Electrical
Verify the unit nameplate agrees with power
supply. WSHP Series units are provided
with single point power wiring connections.
A complete set of unit specific wiring
diagrams, showing factory and field wiring
are located inside the controls compartment
panel.
Note: All units are factory wired for either
208V/230V, 265V, 460V, or 575V. The
transformer configuration must be checked
by a qualified technician prior to service,
especially if unit is to be connected to a
208V or 230V supply. Note: All our units
are default wired to 208V for the
208V/230V option. To utilize 230V service,
interchange the yellow and red wire
terminals from the transformer.
Red-Black for 208V
Yellow-Black for 230V
All units require field supplied electrical
overcurrent and short circuit protection.
Device must not be sized larger than the
Maximum Overcurrent Protection (MOP)
shown on the unit nameplate.
Codes may require a disconnect switch be
within sight of the unit.
A unit-mounted disconnect switch is
available as an option. It is important to note
that this is a method for convenient
maintenance of the unit, but does not
provide unit protection or isolation.
Disconnect all electrical power
sources before servicing the unit.
More than one power source may be
provided. Failure to do so may result
in injury or death from electrical
shock or entanglement in moving
parts.