Static Resistances - York DC180 Installation Manual

NOTE: De-energize the compressors before taking any test
measurements to assure a dry indoor coil.
Supply Air Drive Adjustment
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 Performance Data Tables.
Belt drive blower systems MUST be adjusted 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. Adjustments of the blower speed
and belt tension are REQUIRED. Tighten blower pulley
and motor sheave set screws after these adjustments.
Re-checking set screws after 10-12 hours run time is
recommended.
Table 16: Static Resistances
DESCRIPTION
WET COIL
GAS HEAT
ELECTRIC HEAT OPTIONS
ECONOMIZER OPTION
HORIZONTAL DUCT CONNECTIONS
1. Deduct these resistance values from the available external static pressures shown in the respective Blower Performance Table except for Horizontal
Duct Connections.
Add these values due to less airflow resistance.
Johnson Controls Unitary Products
1
MODEL 180
2.1/4500 2.8/6000
24.8/0.1 24.8/0.1
24.8/0.1 24.8/0.1
18 KW 24.8/0.1 24.8/0.1
36 KW 24.8/0.1 50.0/0.2
54 KW 50.0/0.2 74.4/0.3
72 KW 50.0/0.2 99.2/0.4
24.8/0.1 24.8/0.1
50.0/0.2 74.4/0.3
Note the following:
1. The supply air CFM must be within the limitations shown in
the Blower Performance Tables 13 and 21.
2. Pulleys can be adjusted in half turn increments.
3. The tension on the belt should be adjusted as shown in the
Bet Adjustment, Figure 19.
4. Tighten blower pulley and motor sheave set screws after
any adjustments. Re-check set screws after 10-12 hours
run time recommended.
RESISTANCE, Pa/IWG
3
CFM
m /s/
MODEL 240
3.4/7200 2.8/6000 3.8/8000
24.8/0.1 24.8/0.1 24.8/0.1
24.8/0.1 24.8/0.1 24.8/0.1
24.8/0.1 24.8/0.1 24.8/0.1
74.4/0.3 24.8/0.1 50.0/0.2
99.2/0.4 50.0/0.2 74.4/0.3
149.0/0.6 50.0/0.2 99.2/0.4
24.8/0.1 24.8/0.1 24.8/0.1
124.0/0.5 50.0/0.2 74.4/0.3
5120416-XIM-C-0216
MODEL 300
4.4/9400 3.78/8000 4.25/9000
24.8/0.1 25/0.1 25/0.1
24.8/0.1 25/0.1 25/0.1
24.8/0.1 25/0.1 25/0.1
74.4/0.3 25/0.1 50/0.2
99.2/0.4 50/0.2 75/0.3
149.0/0.6 50/0.2 100/0.4
24.8/0.1 25/0.1 25/0.1
124.0/0.5 50/0.2 75/0.3
4.72/10000
25/0.1
25/0.1
25/0.1
75/0.3
100/0.4
150/0.6
25/0.1
125/0.5
37