Advertisement
For optimum performance, 2 to 3 equivalent diameters of straight
duct should be installed prior to the inlet of the unit. Rectangular
discharge opening is designed for a flanged duct connection. A clear
area around the opening has been left for screw penetration. Fasten
and seal all connections by method prescribed in the job specification.
Minimum Access
Make appropriate accommodations for access panel removal. If unit
is to be installed in hard ceiling/wall application, refer to Nailor
fan powered terminal unit submittals for specific dimensions before
installing to assure there is access to the unit and components after
installation is complete. Nailor 35S fan powered VAV terminal units
have access panels on the top, bottom and side. Nailor 35N units
have only bottom panels. Model 37S and 37N have top and bottom
panels. Removable top and bottom access panels are secured as
standard with screws. However, if the ¼ turn fastener access panel
option is supplied, the bottom panel screws are replaced with two
quick-connect latches.
Units with a removable top access panel are secured with two
additional screws in the middle for shipping and handling. These
additional screws can be removed after the unit is hung for quicker
service if needed.
For low voltage control enclosure access, a minimum of 18" (457) is
recommended. Specific control enclosure location is indicated on
product submittals. Low voltage control enclosures have removable
covers that are attached with sheet metal screws. High voltage
controls enclosures have access panels that are equipped with
hinges. For clearances for full opening of hinged access doors, refer
to project specifications, submittal sheets and NEC.
Important: These recommendations do not preclude
NEC or local codes that may be in effect, which are the
responsibility of the installing contractor.
Field Wiring
All field wiring must comply with NEC and local codes. Disconnect
switches are optional. Wiring diagrams can be found on labels
affixed to the exterior/interior of the control box enclosure. 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 120
VAC on units with 480 or 208 VAC 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. See Table 1 for calculation details.
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 minimum
circuit ampacity (MCA). See Table 1 for calculation details.
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.
Water Pipe Connections
Exercise extreme caution during "sweating" or brazing process of coil
piping to avoid applying excessive heat to components associated
with valve package. This could cause irreversible damage, requiring
immediate replacement of parts. Make sure valves are in full open
Page 2 of 10
Nailor Industries, Inc. reserves the right to change any information concerning product or specification without notice or obligation.
position during brazing process. Heat can be dissipated more
effectively by wrapping a wet towel around the valve body during the
brazing process.
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
NOTE
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:
a. If filters are required, make sure they are installed as intended.
b. Make sure duct system is clear of all debris and foreign objects.
c. Ensure unit enclosure, blower housing and blower wheel are free
of any debris and foreign objects.
Starting the fan motor:
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
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.
original
engineering
drawings.
7-6-23 IOM-FPTU
Advertisement
