Johnson Controls P70 - Page 6

6 P—P70, P72, and P170 Controls for Low Pressure Applications Product/Technical Bulletin
Line
M1
L1
L2
Load
Line
M2
Alarm
Circuit
Power
Alarm
Main circuit (Line to M2) opens and
auxiliary circuit (Line to M1) closes
on pressure rise.
Figure 7: Typical Wiring for 4-wire 2-circuit Switch
(P70G and H Models)
Line
M1
L1
L2
Load
Line
M2
Line to M1 and Line to M2 open on pressure drop.
L3*
*(L3 is third supply line in 3-phase applications.)
Figure 8: Typical Wiring for DPST Switch
(P72A and B Models)
Table 1: Single Pressure Controls Switch Action, Low Event, High Event, and Models
Switch and Action Low Event High Event Models
Single-Pole Single-Throw
(SPST) Open-low
Cut Out
(Opens Line to M1)
Cut In
(Closes Line to M1)
P70A, P70B, P170A
Single-Pole Single-Throw
(SPST) Open-high
Cut In
(Closes Line to M1)
Cut Out
(Opens Line to M1)
P70C, P70D, P170C, P170D
Single-Pole Double-Throw
(SPDT)
Opens 1 to 2 and
closes 1 to 3
Closes 1 to 2 and
Opens 1 to 3
P70E, P70F
4-wire, 2-circuits,
1 N.O., 1 N.C.
Open-low
Cut Out
(Opens M2 to Line and
Closes M1 to Line)
Cut In
(Closes M2 to Line and
Opens M1 to Line)
P70G, P70H
4-wire, 2-circuits,
1 N.O., 1 N.C.
Open-high
Cut In
(Closes M2 to Line and
Opens M1 to Line)
Cut Out
(Opens M2 to Line and
Closes M1 to Line)
P70J, P70K, P170K
Double-Pole Single-Throw
(DPST)
Open-low
Cut Out
(Opens M1 to Line and
M2 to Line)
Cut In
(Closes M1 to Line and
M2 to Line)
P72A, P72B
Double-Pole Single-Throw
(DPST)
Open-high
Cut In
(Closes M1 to Line and
M2 to Line)
Cut Out
(Opens M1 to Line and
M2 to Line)
P72C, P72D