User Guide
System 350 P352P Electronic Proportional Plus Integral Static Pressure Controls 9
e. Adjust the minimum output from 0 to 60% by
turning the potentiometer completely clockwise.
Note: As the potentiometer is adjusted in the
clockwise direction, the P352P’s “V”
output voltage should go from
0 to 6 VDC and the “I” output current
should go from 0 to 12 mA. The LEDs
should turn on, one at a time, from left
to right (until LED 6 is on).
If the LEDs do not come on or the “V”
or “I” outputs do not change as
described above, replace the P352P.
3. Check pressure transmitter for proper output
voltage.
a. Re-adjust the P352P back to the desired control
settings (see the Adjustments section); then
reconnect the pressure transmitter and energize
the blower.
b. Connect the DC voltmeter (+) lead to the P352P
“SN” terminal and the (-) lead to the “C”
terminal; then, using Figure 7, convert the
voltage to pressure (P
T
).
Note: A transmitter output of 0 to 5 VDC
should correspond to a pressure of
0 to 0.5 in. W.C. for the DPT-2640-3 or
to a pressure of 0 to 10 in. W.C. for the
DPT-2640-7 (see Figure 7).
If the voltage conversion to
pressure (PT) deviates substantially from
the actual, replace the transmitter.
If the voltage conversion to pressure at
the transmitter (PT) is close to the actual
pressure, then:
– If the proportional plus integration
control is selected, wait for the
system to stabilize, then verify that
the transmitter pressure (P
T
) is very
close to the selected setpoint
pressure.
– If the proportional only control is
selected, make sure the transmitter
pressure is above the setpoint (for
DA mode) or below the setpoint (for
RA mode).
P
T
Pressure (in. W.C.)
Transmitter "OUT" Voltage (VDC)
5
2.5
0
0
0.25 0.5
(DPT-2640-3)
0 5
10
(DPT-2640-7)
Figure 7: Transmitter Voltage vs. Pressure
4. Check the D352 Display Module.
If there is no D352 in the system, skip this step.
Note: Steps 1 through 3 must be
performed first.
a. Check pressure at the transmitter. The display
should read the same pressure.
b. If the D352 does not read the correct transmitter
pressure (P
T
), replace the D352.
c. Press the setpoint button on the display module
to read the selected setpoint.
d. If the D352 displays a reading other than the
expected setpoint value, check the setpoint
potentiometer setting and correct if necessary. If
the display continues to read an incorrect or out-
of-range (>0.520 in. W.C. for the P352PQ-2C)
value, replace the D352.
Note: If the control and add-on modules all appear to
be operating properly, but the field device still
does not turn on and off as expected, check the
wiring from the P352P to the field device.