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H
B
NO
M
D A M P E R
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Fig. 16 — CSC 3000 Series Reset Volume Controller
7. Balance the supply outlets using a proportional air volume
method.
a. With the blower discharging full volume (SCR on
max setting), measure the total air volume.
b. Calculate the percentage of the design air volume
needed by each outlet.
c. Multiply the total air volume by the percent-of-
design air volume for each diffuser.
d. Balance each outlet according to the requirements
calculated above.
8. Balance the unit fan discharge:
a. Measure the total flow discharging from the unit.
b. Adjust the discharge flow from the unit using the unit
electronic speed control (SCR).
9. Reconnect the damper actuator and/or the thermostat tub-
ing to the velocity controller with the fan still running.
Make sure the piping is as shown on the unit piping/wiring
diagram.
10. Balance the primary (cooling) air volume:
NOTE: To balance the primary air side of the 45M,N,R
unit only, the blower motor must be disconnected.
a. Connect the Magnehelic or inclined manometer (0 to
2.0 in. wg scale, maximum) to the differential pres-
sure sensor tubing.
b. Measure the volume of air flowing through the inlet
using the calibration curve affixed to the unit.
RANC
1) With a 0 psi thermostat signal, measure the unit
maximum airflow.
2) Rotate to the "HI" adjustment knob on the velocity
controller, adjust the airflow to the desired maxi-
mum setting.
3) With the 15 psig (or greater) thermostat signal,
measure the unit minimum airflow.
DANO
1) At a 0 psi stat signal, measure the unit minimum
airflow.
2) Rotate the "LO" adjustment knob of the velocity
controller, adjust the minimum flow to the de-
sired setting, as read from the differential pres-
sure sensor.
3) With a 15 psig (or greater) thermostat signal, mea-
sure the unit maximum airflow.
4) Rotate the "HI" adjustment know on the velocity
controller, adjust the airflow to the desired maxi-
mum setting.
11. Reconnect the power to the blower motor on the 45M,N,R
unit.
T
RESET START
LO STAT ΔP
HI STAT ΔP
RESET SPAN
NOTES:
1. The single function control system uses a KMC CSC 2000
series velocity controller with a rated air consumption of
0.0083 SCFM at 20 psi main air pressure.
2. The maximum and minimum limits are both changed when
adjusting the CENTER knob. For this reason, the center
knob should always be set first.
3. Refer to the Table 15 if any of the above steps do not result
in satisfactory performance.
Table 15 — Troubleshooting Pneumatic Controls
PROBLEM
Controller does not reset to
maximum minimum set point
during balancing procedure
Controller does not reset to
maximum or point during
operation
Pneumatic actuator does not
stroke fully
Air valve stays in wide open
position
Units
with
(Sequences 1306-1317 and 1402-1405)
1. Determine sequence of operation (direct-acting, normally
closed [DANC], reverse-acting, normally closed [RANC],
direct-acting, normally open, or reverse-acting, normally
open). This can be accomplished by reading the diagram
affixed to the unit. All sequences above utilize a four-func-
tion controller, allowing for changeover from a given se-
quence to another.
2. Check the main air pressure at the controller. Main air
should equal 18 to 25 psi. Main air must be clean and dry.
3. Check for primary airflow in the inlet duct, using a differ-
ential pressure sensor tapped into the differential pressure
sensor signal line tees.
4. Verify that the installed room thermostat is compatible with
the unit control.
5. Close the primary air damper.
a. DANC, RANC — Disconnecting the actuator from
the controller should allow the damper to close com-
pletely.
b. DANO, RANO — Connecting a 20 psi air supply
directly to the actuator should close the damper com-
pletely.
6. Start the blower motor by doing one of the following:
45J,K,Q Units:
DANC, RANC, DANO, RANO — Connect electrical
power to the blower motor controls.
45M,N,R Units:
DANC, DANO — Disconnect the thermostat line from the
blower control.
RANC, RANO — Connect the main air line to the blower
control, bypassing the thermostat input.
These steps should energize the fan.
7. Balance the supply outlets using a proportional air volume
method:
a. With the blower discharging full volume (SCR on
max setting), measure the total air volume.
b. Calculate the percentage of the design air volume
needed by each outlet.
c. Multiply the total air volume by the percent-of-
design air volume for each diffuser.
18
LIKELY CAUSE
Thermostat signal is being used for
control signal. An artificial signal must
be used.
Thermostat is not demanding mini-
mum set maximum or minimum air
volume. Main air pressure at the con-
troller is less than 15 psi.
Leak in pneumatic tubing between the
controller and the actuator. Main air
pressure at the controller is less that
15 psi. Leak in the actuator dia-
phragm.
Differential pressure sensor is blocked
or obstructed. Insufficient supply air
pressure in the unit inlet.
Multi-Function
Controllers
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