Reznor YDSA Unit Installation Manual - Manual (Page 36)

Form I-Y, P/N 273646R6, Page 36
Outside Air Only Dampers, Option AR8, AR2D, AR2L, or AR2Y
- The
damper motor is electrically interlocked with the blower (supply fan) motor via an inter-
nal end switch, such that a command to start the fan opens the damper first. When
the damper reaches 80% open, the end switch closes, and the supply fan will operate.
When the supply fan is called to be OFF, the damper closes
NOTE: To verify control
option selection, check the
option listing on the wiring
diagram and the option list
in the APPENDIX, pages 68
thru 73. Outside Air & Return Air Dampers, Option AR25, AR2G, AR2H, or
AR2M - If outside and return air motorized dampers were ordered, there are a variety
of damper control options (Option GF). Some require field installation. If the damper
control sensing option requires field installation of components, the components are
shipped with the unit and include the manufacturer's instructions. Install according to
the instructions and connect the wires according to the unit diagram. Follow the wiring
recommendations in Paragraph 7.5.2.
Senses Option Installation and Function
Remote Damper Control, DDC GF1
Damper position is adjusted by the controller in response to a field-supplied remote 0-10V
input signal.
Two Position Damper Control (open/
closed), DDC
GF2
Sends message to open or close dampers as required. Damper opens to a fixed setpoint
during occupied mode and closes during unoccupied mode.
Four-Position Damper Control GF4
Factory installed to provide four damper settings from two switches. Each input represents a
position. As the input changes, the controller changes the damper position.
Building Static Pressure GF5
Factory installed to monitor building pressure for damper operation. Requires field-installation
of sensor. See instructions in Paragraph 9.1.2 below.
Outside Air Dry Bulb Economizer
w/Dual Reference Enthalpy Control
GF8 Economizer package, CO
2
& Dual Reference enabled.
Inlet Air Damper
Control Options
9.1.2 Power Exhaust,
Option PE__
If equipped with optional power exhaust as illustrated in FIGURE 21, page 35 (Option
AR2D or AR2H), the power exhaust will then be controlled in response to one of the
following control options. Power exhaust opening has gravity dampers.
NOTE: Power exhaust is also a part of airflow configurations that include the energy
recovery wheel (Option AR2L and AR2M) discussed in Paragraph 9.1.3.)
Senses Option Installation and Function
2 Speed Fan Control Based on
Active Heating or Cooling Mode EFC1
Exhaust airflow is factory set to order specifications but is adjustable via the unit controller.
Building Static Pressure EFC4
Factory installed to monitor building pressure for exhaust operation. Requires field-installation of
sensor. See instructions below.
Supply Fan Tracking with
Adjustable Offset
EFC7
Power exhaust is set to operate in relation to the supply fan. The offset is adjustable via the unit
controller.
Constant Volume EFC9 Exhaust airflow is factory set to order specifications but is adjustable via the unit controller.
Power Exhaust Control
Options
Instructions for Field-
Installed Building Static
Pressure Sensor in
Option GF5 or Option
EFC4
During startup, the CFM will need to be checked for the supply fan and optional exhaust
fan. Follow the instructions in Paragraph 10.3 to use the unit interface TAB Menu and
the airflow / pressure drop chart on pages 69 thru 73 to determine the airflow settings.
Setting Exhaust Fan
CFM
Tranducer in the
Control Compartment
Tubing Requirements - All tubing is field supplied. The transducer is equipped with
1/4” O.D. pressure fittings for the pressure signal connection. Both the positive (high)
pressure port and the reference (low) pressure port are located on the front of the
transducer, labeled “HIGH” and “LOW” respectively.
For best results (shortest response times), 3/16” I.D. tubing is suggested for tubing
lengths up to 100 feet (30M), 1/4” I.D. for tubing lengths up to 300 feet (91M), and 3/8”
I.D. for tubing lengths up to 900 feet (274M)
Building Pressure Control Pickup Tubes
- Both pickup tubes for building pressure con-
trol are field supplied. Install a pickup tube in the building. To sense atmospheric pres-
sure, route the tubing to one of the small holes in the cabinet panel and install a field-
supplied pickup tube designed for outdoors.
As determined by the application, attach the tubing from the positive (high) pressure
pickup to the “high” connection on the transducer and the reference (low) pressure
pickup tube to the “low” connection on the transducer.
Verify Installation and Operation
- Be sure that tubing connections are correct and
attached securely. On startup, verify that there is a pressure reading displayed on the
unit controller.
NOTE: Same type as Option
VFC4. For additional infor-
mation, see
Paragraph 8.2.
9.1 Inlet Air and Exhaust Air Options (cont’d)
9.0 Optional Equipment including Heat Sections (cont’d)