Nailor 37S Manual page 118

Field Wiring
All field wiring must comply with NEC and local codes. Disconnect
switches are optional. Also, electrical, control, and piping diagrams
can be found on labels affixed to the exterior/interior of the control
enclosure box. Unless specifically requested by customer, all units
are wired for a single point connection to the fan and electric heater
(if present). All electric heaters will be staged per specification.
Motors rated for 277 or 120VAC on units with 480 or 208VAC
ratings respectively are always connected between the neutral and
L1 terminals. The installing electrician should rotate the incoming
electric service by phase to help balance the building electric load.
Fuse size designates the size of the internal fuse if it is supplied.
Maximum Overcurrent Protection (MOP) designates the largest
breaker or fuse in the electrical service panel that can be used to
protect the unit.
ELECTRICAL SUGGESTIONS AND REQUIREMENTS:
1. Provide a safety disconnect per NEC 424-19, 20, 21
2. Disconnect the power supply before wiring or servicing unit.
If a disconnect switch is present, it should be in the OFF
position while making power connections or repairs.
3. All units with electric heat should have copper wires sized
for 125% of Nameplate Amperage.
4. Follow wiring diagrams and instructions mounted on the
unit. 480V/3 phase heaters, for example, require a neutral
wire in addition to the full sized ground wire. NEC 424-15
and 250 also require that all units be grounded.
Control Start-up and Operation
Your local Nailor Representative can provide detailed information
about start-up and operating procedures for Nailor's digital, analog,
and pneumatic controls. For specific information on controls
provided by other manufacturers contact the control manufacturer's
local or national office. This applies whether the controls were
factory or field installed.
Note: Digital controllers may use specific communication
addresses based on Building Management Systems,
Architecture and original engineering drawings. Installing the
terminal in a location other than that noted on the label may
result in excessive start-up labor.
Primary Air Damper and Fan Adjustment
Before starting the fan motor, make sure duct system is free of
foreign objects, and filters are installed where required.
(1) Start motor and let it run-in at least 15 minutes. During run-in,
check ductwork connections for leaks and repair if necessary.
(2) All Nailor fan powered VAV terminal units incorporating PSC
motors use a solid state SCR speed controller to adjust motor
speed and consequently air volume. Speed controllers have built-in
maximum and minimum stops as detailed on the fan performance
pages in the Nailor VAV Terminal Unit catalog. Turning the manual
fan speed control counterclockwise will increase the fan speed;
clockwise will decrease speed. The fan speed control is located on
the side of the motor controls enclosure.
(3) For series units, set the unit to full cooling. Adjust and set
primary maximum cfm by measuring the airflow with a manometer
attached between the gauge ports in the pneumatic tube leading to
the high and low sides of the inlet air pick-up. A chart is attached to
the side of the unit showing airflow vs. pressure for different inlet
sizes. Adjust and set remote balancing dampers, if present. Do not
worry about airflow at this time; just proportion the outlets with the
dampers. Be sure to leave the dampers in the most possible open
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position. This will generate the minimum noise level. Adjust the fan
speed control until the required CFM is obtained (by measuring the
air quantity at the room outlets or by zeroing the induction air if
primary and fan match). Fan should be adjusted with primary air at
maximum set point to ensure that no supply air is discharged at the
induction port. Recheck the fan and primary airflows when the
damper is reset to the minimum set point.
(4) For parallel units, turn the fan off, and set the primary air in the
same manner as described for series units. Proportion the diffusers
as above. Reset the primary airflow to the design fan turn-on point.
Measure the airflow again to verify proper airflow. Turn the fan on.
Allow the primary air damper to come under control after the fan is
started, and then adjust the fan until the prescribed airflow is
achieved by measuring the air quantity at the room outlets. Be sure
to allow the primary air damper to stabilize after each fan
adjustment and prior to measuring the airflow. Turn the fan off and
verify the minimum airflow point on the damper.
(5) For units equipped with ECM motors, set the primary air
dampers as described in (3). Set the fan as described on the ECM
MOTORS IOM, page 1. Proportion the dampers after the fan is set.
Remember to adjust the dampers so that they are in the most open
condition after proportioning. This will generate the minimum noise.
Maintenance Procedures
Fan and Motor
Nailor fan powered terminal units are equipped with permanently
lubricated motors. Inspect fan and motor assembly for dust and dirt
as often as dictated by operating environment. Clean assembly if
necessary.
If fan motor does not run, do the following:
a. Check for free rotation of blower wheel. Make sure no foreign
objects are in fan. Look for signs of freight or job site damage.
b. Check power supply. Disconnects should be in the "ON"
position.
Optional fusing should also be inspected. Check transformer for
proper output.
c. Check for proper control signals and PE switch setting (if
provided) and relay function.
Fan motor runs but emits excessive noise:
a. Maximum airflow may be too high, or discharge static
pressure may be incorrect.
b. Blower may have clearance problems. Make sure all
components are securely attached.
c. Verify integrity of ductwork. Leaks or loose connections
could cause noise. Check for rattling diffusers or rattling or
incorrectly adjusted balancing dampers.
Fan motor runs, but airflow too low:
a. May be due to ductwork restrictions, dirty air filters,
or clogged water coils.
b. Readjust fan speed control.
c. Discharge static pressure may be incorrect.
Check balancing dampers.
3/05 IOM-FPTU