Ingersoll-Rand ReliaTel, Manual, Page: 50 / 176

50 RT-SVD03L-EN
To change the maximum airflow, adjust the R-136
potentiometer on the RTOM.
N No otte e:: Voyager
™
units use this potentiometer to set the
discharge air setpoint limit.
Figure 34. Adjusting airflow
7
6
5
4
3
2
1
J4
3
2
1
R40
R42
DA Cool - Fan SPD
TP 1
Meaure from this test point to
ground to read CFM/Ton
R136
RTOM R136 potentiometer adjusts the maximum
indoor fan CFM/speed. Adjust in test mode cool 2
RTOM
To verify the proper cfm setting, measure the DC
voltage on the test point (TP1) next to R-136 and
compare it to the "cfm vs. vdc chart". The cfm vs. vdc
chart is located on a sticker on the fan housing itself
and in the unit Installation, Operations, and
Maintenance manual (IOM).
Indoor Fan Control Description;
Backwards Curved (BC) Plenum Fan
Control - Unit Identification
Digit 15 in the model number indicates whether the
unit has a standard constant volume, multi-speed or
SZVAV fan operation.
Examples:
• YSC120FWRLA01D6E0A1060004 is a SZVAV unit.
• YSC120FWRLA01D7E0A1060004 is a multi-speed
unit.
• SC120FWRLA01D0E0A1060004 is a standard
constant volume indoor motor.
Wiring and Configuration
7.5 to 10 ton high efficiency (YHC092-120) and 10 ton
standard efficiency (YSC120) Precedent
™ units use a
constant torque, backwards curved (BC), indoor fan
motor. Airflow is controlled by a 0 to 10 vdc output
signal from the J11 header of the RTOM. Unlike the 17
Plus products this voltage level directly corresponds to
fan rpm and not cfm.
Figure 35. 17 Plus 7.5-10 Tons airflow configuration
Measure the PPF-IDFRPM wire harness to check the
"Potentiometer Voltage" output.
Proper wiring configuration is required for correct unit
operation. Wiring harness plugs should be configured
as shown below for 7.5 to 10 ton Precedent
™ units.
Figure 36. Precedent ™ ™ 7.5 to 10 tons SZVAV
configuration
S Siin ng glle e Z Zo on ne e V VA AV V,, M Mu ullttii--S Sp pe ee ed d a an nd d 1 17 7 P Pllu uss