McQuay Skyline IM777, Руководство по установке и обслуживанию

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IM777 Page 11
Water heating coils
1. Water supply and water return connections extend through
the end panel of the coil section. All connections are
labeled on the end panel.
2. Water supply and water return connections are male
N.P.T. iron pipe.
3. When installing couplings, do not apply undue stress to
the connection extending through unit panel. Use a
backup pipe wrench to avoid breaking the weld between
coil connection and header.
4. Follow recommendations of the control manufacturer
regarding types, sizes, and installation of controls.
5. Hot water coils are not recommended for use with enter-
ing air below 40°F.
6. If fresh air and return air are to be heated by a hot water
coil, care should be used in the design of the system to
provide thorough mixing before air enters the coil.
7. For preparation of coils for winter operation, see “Winter-
izing Water Coils” on page 23 .
Drain Pan Traps
Drain lines and traps should be run full size from the drain
pan connection. Drain pans should have traps to permit the
condensate from the coils to drain freely. On both blow-
through and draw-through units, the trap depth and the dis-
tance between the trap outlet and the drain pan outlet should
be twice the static pressure in the drain pan section under
normal operation for the trap to remain sealed.
See Figure 18.
Figure 18. Allow adequate distance between trap outlet
and drain pan
Note: The door panels on some applications have a close
clearance over the drain pipes. Extend the drain fitting with a
coupling if necessary for door clearance.
See Figure 19.
Note: Outdoor drain traps should be made of a material that
can withstand freezing temperatures.
Note: Drain traps that dry out can allow cold air to seep into
the equipment.
Figure 19. Extend drain fitting for door clearance
Internal Isolation Assembly
Adjustment
On units with internally isolated fan and motor assemblies,
the assemblies have been secured for shipment with a tie-
down at each point of isolation.
Before operating the unit:
Remove the shipping brackets and tie-down bolts and dis-
card. The shipping brackets located on the opposite drive
side of the unit are difficult to access from the drive side of
the unit. Either remove them before the unit is assembled,
or remove the panel on the opposite drive side to gain
access.
See Figure 20.
The spring isolators under the four corners of the fan and
motor assembly have been factory adjusted while the fan was
not running.
See Table 1 . With the unit operating at normal
cfm and static pressure, the isolators should all be at the same
height opening. If adjustments are required, loosen the 1/2"
capscrew on top of the isolator and turn the adjusting bolt to
lower or raise the fan and motor base. Retighten the capscrew
when adjustments are completed.
Table 1: Factory spring mount adjustments
P r e s s u r e ( P )
a t t h e d r a i n p a n
2 P
2 P
SPRING MOUNT ADJUSTMENT AT REST
Fan Discharge
Position
Top or Bottom Horz.
H
Downblast
H
Upblast H
1 3.75 3.75 4.25
2 4.25 3.75 4.25
3 4.25 3.75 4.25
4 3.75 3.75 4.25
C l e a r a n c e
D r a i n