Air Balance; Checking Air Quantity; Indoor Blower Specifications; Power Exhaust Specifications - York ZR Series Installation Manual

5167531-YIM-J-1019
Table 21: Indoor blower specifications
Size
Model
(tons)
HP
1-1/2
078
ZR
(6.5) 2
090 1-1/2
ZR
(7.5)
3
102 2
ZR
(8.5)
3
120 2
ZR
(10) 3
3
150
ZR
(12.5) 5
Table 22: Power exhaust specifications
Model Voltage
2PE04704706 208/230-1-60
2PE04704746 460-1-60
2PE04704758 575-1-60
1. Motors are multi-tapped and factory wired for high speed.

Air balance

Start the supply air blower motor. Adjust the resistances in both
the supply and the return air duct systems to balance the air
distribution throughout the conditioned space. The job
specifications may require that this balancing be done by
someone other than the equipment installer.
You must adjust the belt drive blower systems to the
specific static and CFM requirements for the application.
The belt drive blowers are not set at the factory for any
specific static or CFM. You must adjust the blower speed
and belt tension.
Verify proper sheave alignment. Tighten the blower
pulley and motor sheave set screws after these
adjustments. Re-check the set screws after 10-12 hours
of run time.

Checking air quantity

Method one
1. Remove the dot plugs from the duct panel. See Figures 12
and 13.
2. Insert eight-inches of 1/4 inch metal tubing into the airflow
on both sides of the indoor coil.
Note: You must insert the tubes and hold them in a position
perpendicular to the air flow so that velocity pressure
does not affect the static pressure readings.
46
Motor
RPM Eff. SF Frame
1725 0.8 1.15
1725 0.8 1.15
1725 0.8 1.15
1725 0.8 1.15
1725 0.8 1.15
1725 0.8 1.15
1725 0.8 1.15
1725 0.8 1.15
1725 0.8 1.15
1725 0.87 1.15
Motor
1
HP RPM QTY
3/4 1075
3/4 1075
3/4 1050
Motor sheave
Datum dia.
Bore (in.)
(in.)
56 3.4 - 4.4 7/8
56 3.4 - 4.4 7/8
56 3.4 - 4.4 7/8
56 3.4 - 4.4 7/8
56 3.4 - 4.4 7/8
56 3.4 - 4.4 7/8
56 3.4 - 4.4 7/8
56 3.4 - 4.4 7/8
56 3.4 - 4.4 7/8
184T 4.3 - 5.3 1-1/8
Unit (per circuit)
LRA FLA
1 24.9 5
1 N/A 2.2
1 N/A 1.5
3. Use an inclined manometer or Magnehelic® to determine
the pressure drop across a dry evaporator coil. The
moisture on an evaporator coil can vary greatly, measuring
the pressure drop across a wet coil under field conditions
could be inaccurate. To ensure that the coil is dry, de-
activate the compressors de-activated while the test is
being run.
Note: De-energize the compressors before you take any test
measurements to ensure that the evaporator coil is dry.
4. Use the pressure drop indicated by the manometer and the
graph in Figure 30 to determine the unit CFM. In order to
obtain an accurate measurement, verify that the air filters
are clean.
5. To adjust measured CFM to required CFM, see Supply air
drive adjustment on page 48.
6. After you note the readings, remove the tubes and replace
the dot plugs.
7. Tighten the blower pulley and motor sheave set screws
after any adjustments. Re-check the set screws after 10-12
hours run time.
Failure to properly adjust the total system air quantity
can result in extensive blower damage.
Method two
1. Drill two 5/16 inch holes, one in the return air duct as close
to the inlet of the unit as possible, and another in the supply
air duct as close to the outlet of the unit as possible.
Blower sheave
Datum dia.
Model Bore (in.)
(in.)
1VM50 7.0 1
1VM50 6.0 1
1VM50 7.0 1
1VM50 5.7 1
1VM50 8.5 1
1VM50 7.0 1
1VM50 8.0 1
1VM50 7.0 1
1VM50 7.0 1
1VP56 6.7 1
Fuse size
MCA
6.3 10
2.8 5
1.9 4
Johnson Controls Ducted Systems
Belt
Model
AK74 A49
AK64 A49
AK74 A49
AK61 A49
AK89 A56
AK74 A54
AK84 A56
AK74 A54
AK74 A54
BK77 BX55
CFM @
0.1 ESP
4800
4800
4800