Product Overview

P-3800 Product Bulletin 5
Commissioning
The following instructions
assume that the P-3800 Reset
Volume Controller to be installed
is for a retrofit/replacement
installation.
If the P-3800 is for a new (OEM)
installation, proceed directly to
Step 4.
Pre-Commissioning Setup
1 . Before removing the
existing reset volume
controller, identify the five
air lines connected to the
device (supply, output, high
pressure pickup, low
pressure pickup, and
thermostat) and label them
appropriately.
2. With the HVAC system ON,
remove the existing reset
volume controller from its
mounting bracket and
disconnect the air lines.
Leave the existing mounting
bracket in place for use
when installing the new
P-3800.
3. Using the supply source
available (typically
20 PSIG), blow out the high
and low pressure pickup
lines (identified in Step 1) to
remove any contaminants
that may interfere with
proper system air flow and
delivery to the P-3800.
4. Tee a magnehelic gage or
manometer into the high
and low pressure pickup
lines leading from the duct.
Doing so will provide
pressure indication required
in future steps.
Reset Range Adjustment
5. The indicator on the reset
range adjustment slider of
the P-3800 (see Fig. 6) is
factory set at approximately
1.2 in. WG (299 Pa). The
desired reset range is the
difference between the
desired maximum and
minimum flow set points, as
measured in inches water
gage velocity pressure (see
Fig. 4). Before connecting
any of the existing air lines
to the P-3800, loosen the
slider locking screw and
move the reset range
adjustment slider to the
desired reset range (as
indicated on the VAV box or
the system drawing).
Tighten the slider locking
screw to secure the reset
range adjustment slider at
the desired setting.
Thermostat Reset Start
Point Adjustment
6. The thermostat reset start
point adjuster on the P-3800
(see Fig. 6) is factory set at
approximately 8 PSIG (56
kPa) for the P-3800-1 and 3
PSIG (21 kPa) for the P-
3800-2, as indicated by the
hash mark located on the
adjustment cam (see Fig.
7), and will likely not require
additional adjustment. If
adjustment is required,
using a 1/4 in. blade
screwdriver, rotate the
thermostat reset start point
adjuster to the desired
setting, in the direction
indicated by the arrow
molded into the P-3800
body. To do so, carefully
pry up on the adjustment
cam using the integral pivot
until a soft "click" is heard.
Check that the adjustment
cam is rotating with each
"click" by noting a change in
position of the hash mark.
Each "click" represents an
increase of 1 PSI (7 kPa).
Note: If the desired
thermostat reset start point
setting is passed, continue
rotating the thermostat reset
start point adjuster in the
direction indicated by the
arrow until a loud "click" is
heard. At this point, the
thermostat reset start point
adjuster is now set at
approximately 3 PSIG
(21 kPa) and the adjustment
can be restarted.