Williams AH Installation, Operating, & Maintenance Instructions page 5

upstream from the chilled water coil. The controls are
wired so that either the chilled water coil is operating
or the hot-water coil is operating, but not both at the
same time. When the conditioned space thermostat is
satisfied, both the chilled and hot water control valves
are deactivated. The same rule applies for inlet and
outlet locations as explained above in "Two Pipe Coils"
(See diagram 2). Each chilled and hot water coil is
controlled individually so a pipe sensor is not required.
HOSE KITS
When hose kits are being used on units it is important
to make sure the hoses are not installed over any
electrical components, such as j-boxes, actuators, etc.
Hoses are not sweat proof so they can condensate. It
is recommended that the flex hoses be field insulated
during installation. Before installing flex hose visually
examine the metallic sealing surface and verify it is flat
and smooth with no sharp edges or deep scratches.
Verify that the sealing gasket is properly installed/
inserted onto the end of the hose. When installing
threaded union connection do not over tighten, this
may cause damage to the gasket seal or sealing surface
and subsequently leak at joint. Proper hose installation
TWO PIPE COIL DIAGRAMS - 2 PIPE COILS (RIGHT HAND SHOWN LEFT HAND OPPOSITE)
OUTLET (TYP)
INLET (TYP)
FOUR PIPE COIL DIAGRAMS - 4 PIPE COILS (RIGHT HAND SHOWN LEFT HAND OPPOSITE)
OUTLET (TYP)
INLET (TYP)
1 ROW HW
(REHEAT)
1 2 1 2 3
2 ROW 3 ROW
1 1 2 3
3 ROWS 2 ROWS HW
CHW (REHEAT)
STANDARD
practice is to had tighten the union, then use wrench
to further tighten no more than a 1/4 turn. Do not apply
pipe dope or thread sealant to sealing surface or pipe
threads. Ensure the joints are leak free before starting
up unit. If leak is observed slightly tighten the fitting not
exceeding an additional 1/4 turn. Failure to follow these
directions may cause unit leak or operation failure.
WILLIAMS MODEL IDENTIFICATION
The following model numbers indicate the number of
rows and type of chilled and hot water coils. Williams
standard coil has the hot water coil located in the
reheat position.
AH008W2B40 = W2 indicates a two pipe water coil
AH008W4B40 = W4 indicates a four pipe water coil
AH008W2B40 = 40 indicates four row, chilled water;
0 row hot water (first digit = chilled water,
second digit = hot water)
AH008W4B42 = 42 indicates four row, chilled water;
2 row hot water
LV008W2B02 = 02 indicates 0 row, chilled water;
2 row hot water (heating unit only)
1 2 3 4
AIR
FLOW
(TYP)
4 ROW
1 2 3 4
1 2
AIR
FLOW
(TYP)
4 ROW CHW
1 2 3 1
AIR
FLOW
(TYP)
3 ROWS CHW 1 ROW HW
(REHEAT)
SPECIAL ORDER
(HEATING COIL LOCATED IN THE
PREHEAT POSITION)
WILLIAMS AIR HANDLER MODELS AH / AV 5