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Fan Powered Terminal Units IOM
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 desired
setting, as read from the differential pressure sensor.
With a 15 psig (or greater) thermostat signal, measure
the unit maximum airflow.
3.
Rotate the “HI” adjustment knob on the velocity
controller; adjust airflow to the desired maximum
setting.
11. Reconnect the power to the blower motor on the KLPP,
KQFP & QFV unit.
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 19 — Troubleshooting if any of the
above steps do not result in satisfactory performance.
UNITS WITH MULTI-FUNCTION CONTROLLERS (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-function controller, allowing for changeover from a
given sequence 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
differential 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
completely.
b.
DANO, RANO — Connecting a 20 psi air supply directly
to the actuator should close the damper completely.
6. Start the blower motor by doing one of the following:
KLPS, KQFS, & QFC Units:
DANC, RANC, DANO, RANO — Connect electrical power
to the blower motor controls.
KLPP, KQFP & QFC Units:
DANC, DANO — Disconnect the thermostat line from the
blower control.
RANC, RANO — Connect the main compressed 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.
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 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 volumes:
NOTE: To balance the primary air side of the KLPP,
QFV & KQFP units only, the blower motor must be
disconnected.
a.
Connect a Magnehelic or inclined manometer (0 to 2.0
in. wg scale, maximum) to the differential pressure
sensor tubing.
b.
Measure the volume of air flowing through the inlet
using the calibration curve affixed to the unit.
c.
Adjust the “LO STAT” knob, with a 0 psi thermostat
signal, to obtain the desired airflow setting.
Depending on the control sequence desired, the “LO STAT”
knob will vary either the minimum setting or the maximum
setting as follows:
DANC — “LO STAT” knob adjusts the minimum setting.
RANC — “LO STAT” knob adjusts the maximum setting.
DANO — “LO STAT” knob adjusts the minimum setting.
RANO — “LO STAT” knob adjusts the maximum setting.
OPERATION SEQUENCES
1. During maximum thermostat cooling demand, the
primary air damper will open in the maximum airflow
setting providing cold primary air at the preset maximum
volume. Accessory coils, if supplied, are off, and the unit
should discharge primary air only.
2. When the thermostat modulates between maximum
cooling and satisfied set point, the primary air damper
responds by proportional settings. Accessory coils, if
sup-plied, are off. The KLPS, QFC & KQFS units only will be
Summary of Contents for KLPP
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