Table of Contents
Advertisement
START-UP
Initial Check
IMPORTANT: Do not attempt to start unit, even
momentarily, until all items on the Controls Start-Up
Checklist (in installation instructions) and the follow-
ing steps have been completed.
1. Verify unit has been installed per the Installation
Instructions included in the unit installation packet.
2. Verify that all auxiliary components (sensors, controls,
etc.) have been installed and wired to the unit control
boxes per these instructions, the unit Installation
Instructions, and the unit wiring label diagrams.
3. Verify that air pressure hoses (static, duct, etc.) are
properly attached, routed, and free from pinches or
crimps that may affect proper control operation.
4. Set any control configurations that are required (field-
installed accessories, etc.). The unit is factory config-
ured for all appropriate factory-installed options with
the applicable controls programmed to the default val-
ues. See Adjusting Set Points section on page 46 for
configuration values.
5. Enter unit set points. The unit is shipped with the set
point default values shown in Adjusting Set Points sec-
tion on page 47. If a different set point is required,
change per the example shown under Set Point Func-
tion section on page 47.
6. Configure schedule subfunctions: occupied, unoccu-
pied, and holiday periods. See Program Time
Sequences section on page 52 for details on setting
periods.
7. Verify that control time periods programmed meet cur-
rent requirements.
8. Check tightness of all electrical connections.
9. Perform quick test (see Quick Test section on
page 86).
Set Fan Status and Check Filter Switches
SUPPLY FAN STATUS SWITCH (FS) — A snap-acting
single-pole, double-throw (SPDT) differential pressure switch
is factory mounted in the unit auxiliary control box. The switch
senses the change in pressure across the supply-air fan and pro-
vides the fan status. A length of fire-retardant control (plenum)
tubing connects the switch to the probe located in the fan dis-
charge plenum.
The switch must be set prior to unit operation. To set the
switch, turn the adjustment screw on top (center) of switch
clockwise to increase set point, or counterclockwise to de-
crease set point. The set point switch range is 0.05 to 2.0 in. wg
with a deadband of 0.02 in. wg at minimum set point and
0.1 in. wg at maximum set point.
Set switch so that contact makes to NC when supply-air fan
is energized. Adjust switch with VFD at slow speed on VAV
units. If IGVs are used, adjust switch with IGVs closed. The
switch should make (fan on) within 1 minute after supply-air
fan is energized and break (fan off) within 1 minute after the
fan is deenergized.
CHECK FILTER SWITCH (CFS) — A snap acting SPDT
switch is factory mounted in the unit auxiliary control box. The
switch senses the differential pressure and provides the micro-
processor module with a signal for filter status. Two lengths of
plenum tubing connect the switch to probes located both up-
stream and downstream of the unit filters.
The switch must be set prior to unit operation. To set the
switch, turn the adjustment screw on top (center) of switch
slowly clockwise to find the "pivot" point where the filter sta-
tus still reads clean under
Check the switch operation with the supply-air fan running,
the VFD at slow speed (if applicable), and nominal cfm deliv-
ery. If IGVs are used, adjust switch with IGVs closed. See
Table 45 for clean filter pressure drops for help in locating the
"pivot" point. Once this point is found, turn the screw clock-
wise to obtain the set point at which the filter status will be
dirty. Use Table 45 as a guide.
Table 45 — Filter Switch Set Point
FILTER TYPE
2-in. Throwaway
2-in. Pleated
Bag With Pre-filters
Auxiliary Switch, Power Exhaust —
the modulating power exhaust option have 2 auxiliary switches
mounted on the cams inside the power exhaust damper motor.
The switch cam is factory set to energize the second power ex-
haust motor. A pointer is printed on the red cam and the num-
bers 35 and 63 are both printed on the blue cam. See Fig. 36.
If the damper motor has been replaced or improper opera-
tion is suspected, perform the following test before attempting
to adjust the switch cams:
1. Put the unit into the standby mode.
2. a. For size 034-048 units: Remove damper motor top
cover and verify that pointer points at number 35. If
installing new motor, use screwdriver to turn blue
cam so pointer lines up with the number 35. See
Fig. 37.
b. For size 054-104 units: Remove damper motor top
cover and verify that pointer points at number 63. If
installing new motor, use screwdriver to turn blue
cam so that pointer lines up with the number 63.
See Fig. 37.
3. Enter quick test function (
you reach the PERD display.
4. Press the
ENTER
power exhaust motor no. 2 energized? Yes/No
5. Press the
key again and wait 30 seconds. Was
ENTER
power exhaust motor no. 2 energized? Yes/No
6. Press the
key again and wait 30 seconds. Was
ENTER
power exhaust motor no. 2 deenergized? Yes/No
7. Press the
key again and wait 30 seconds. Was
ENTER
power exhaust motor no. 2 deenergized? Yes/No
8. Exit the quick test. See Quick Test section on page 86
for details.
9. Proceed with evaluation below.
If the answers in Step 5 and Step 7 above were both yes, the
switch cams are properly adjusted. If the answers to either Step
4 or Step 6 above were yes, the switch cams need adjustment.
To adjust auxiliary switch cams:
1. Remove damper motor top cover.
46
in the HSIO display.
INCREASED
PRESSURE
APPROXIMATE
DROP TO
CLOCKWISE
"DIRTY" FROM
TURNS
PIVOT POINT
0.30 in. wg
0.75 in. wg
0.75 in. wg
All units with
) and press
key once and wait 30 seconds. Was
2
5
5
until
Advertisement
Table of Contents
Troubleshooting
