Basic Controls—System 350 P352AB Electronic Pressure Control Series Product/Technical Bulletin
3
Direct/Reverse Acting Mode
The P352AB controls utilize jumpers (at Jumper
Terminal J1) to select the operation mode. (See
Adjustments (P352AB Control)
section and Figure 3.)
When in
Direct Acting (DA) mode
, the relay
de-energizes when the pressure drops below the
setpoint. When the pressure rises above the setpoint
plus
the differential, the relay energizes and the “ON”
LED illuminates.
When in
Reverse Acting (RA) mode
, the relay
de-energizes when the sensed pressure rises above
the setpoint. When the pressure drops below the
setpoint
minus
the differential, the relay energizes and
the “ON” LED illuminates.
Note:
The P352AB controls are configured for DA
mode at the factory.
Refer to Figure 5 for an example of a typical Direct
Acting/Reverse Acting application.
D
imensions
1-3/16
2-3/8
(61)
7/16
(11)
1-1/2
(40)
1/8 (4)
DIN Rail
Mount
7/8 (22) Conduit
Hole
Mounting Slots
For No. 6 Screws
5 (127)
2-15/16 (75)
2-3/8 (61)
7/8 (22)
2-1/4 (57)
(2.0 m)
13 ft
(4.0 m)
or
Wiring Harness
6-1/2 ft
P399 Transducer
CONTROLS
CONTROLS
JOHNSON
O
O
ON
P352
Figure 2: P352AB Control Dimensions, in. (mm)
M
ounting
The P352AB Electronic Pressure Control is housed in
a compact NEMA 1 plastic enclosure designed for
standard 35 mm DIN-rail mounting. Four key-slot
mounting holes on the back of the control case are
provided for surface mounting. (See Figure 2.)
Note:
When mounting the P352AB control (or any
System 350 Module) to rigid conduit, attach
the hub to the conduit before securing the hub
to the control enclosure.