Phasing; Checking Supply Air Cfm - York SUNLINE 2000 Installation Manual

175245-YIM-C-1008

PHASING

®
YORK MODEL BQ, units are properly phased at the
factory. 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 mis-
phased. Change the phasing of the Field Line Con-
nection at the factory or field supplied disconnect
to obtain proper rotation. (Scroll compressors operate
in only one direction. If the scroll is drawing low amper-
age, has similar suction and discharge pressures, or
producing a high noise level, the scroll is misphased).
Scroll compressors require proper rotation to
operate correctly. Units are properly phased at
the factory. Do not change the internal wiring to
make the blower, condenser fans, or compres-
sor rotate correctly.

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.
Belt drive blower systems
the specific static and CFM requirements for
the application. The belt drive blowers are
set at the factory for any specific static or
CFM. Adjustments of the blower speed an belt
tension are
REQUIRED
and motor sheave set screws after these
adjustments. Re-checking set screws after 10-
12 hrs. run time is recommended.
High speed drive accessories (containing a smaller
blower pulley and a shorter belt) are available for appli-
24
be adjusted to
MUST
NOT
. Tighten blower pulley
cations requiring the supply air blower to produce
higher CFM's and/or higher static pressures. Use
Model 1LD0417 for this 20 ton unit. Refer to the Blower
Motor and Drive Data Table 17.
Note the following:
1. The supply air CFM must be within the limitations
shown in the Unit Application Data Table 1.
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 14.
4. Tighten blower pulley and motor sheave set screws
after any adjustments. Re-check set screws after
10-12 hrs. run time is recommended.
FIGURE 14 - BELT ADJUSTMENT
Johnson Controls Unitary Products