Phasing; Checking Supply Air Cfm; Charging Chart - 25 Ton; Belt Adjustment - York SUNLINE MagnaDRY DR180 Installation Manual

350
330
310
290
270
250
230
210
190
170
150
55
Both fans must be running when charging the unit. One fan may switch off at low ambient temperatures making this chart inaccurate.
FIGURE 16 - CHARGING CHART - 25 TON

PHASING

Check for proper compressor rotation. If the blower or
compressors rotate in the wrong direction at start-up,
the electrical connection to the unit is misphased.
Change the incoming line connection phasing to obtain
proper rotation. (Scroll compressors operate in only
one direction. If the scroll is drawing low amperage,
has similar suction and discharge pressures, or pro-
ducing a high noise level, the scroll is misphased).
Scroll compressors require proper rotation to
operate correctly. Do not change the internal
wiring to make the blower, condenser fans, or
compressor rotate correctly. Change the
incoming power to the main terminal block to
obtain proper rotation.

CHECKING SUPPLY AIR CFM

The RPM of the supply air blower will depend on the
required CFM, the unit accessories or options and the
static resistances of both the supply and the return air
duct systems. With this information, the RPM for the
supply air blower and the motor pulley adjustment
(turns open) can be determined from the Blower Per-
formance Data Tables.
Note the following:
1. The supply air CFM must be within the limitations
shown in the Unit Application Data Table 1.
52
DR300 Charging Chart
60 65 70
Suction Pressure (psi)
Outdoor Temp (ºF)
75 80
2. Pulleys can be adjusted in half turn increments.
3. The tension on the belt should be adjusted as
shown in the Belt Adjustment Figure 17.
PROCEDURE FOR ADJUSTING BELT TENSION:
Loosen nuts (A) (top and bottom).
1.
2. Adjust the tension by turning bolt (B).
3. Never loosen nuts (C) from each other.
Use a belt tension checker to apply a perpendicular force to be one belt at the
4.
midpoint of the span as shown. The deflection force should be applied
until a specific deflection distance of 4mm (5/32") is obtained. To determine
the deflection distance from normal position, use a straight edge from
sheave to sheave as a reference line. The recommended deflection force
is as follows:
DEFL FORCE
(A)
Tension new belts at the max. deflection force recommended for the belt
section. Check the belt tension at least two times during the first 24 hours of
operation. Any re-tensioning should fall between the min. and max.
deflection force values.
5. After adjusting, re-tighten nuts (A).
FIGURE 17 - BELT ADJUSTMENT
127915-YIM-A-0405
115º
105º
95º
85º
75º
65º
85
(B)
*Never Loosen
(C)*
Unitary Products Group