Wiring - PENN Controls - LIT-12012399 - P77AAA - P77BCA - P77BEA - P78LCA - P78MCA - Electromechanical Pressure Control - P77 Single Pressure Control - P78 Dual Pressure Control

P77 and P78 Series Controls for Single and Dual Pressure Applications Product Bulletin
Brand
PENN Controls
Product name
P77 Single Pressure Control
P78 Dual Pressure Control
Document type
Product Bulletin
Document number
LIT-12012399
Revision date
2020-10-28
Language
English

See Figure 1 and Table 1 for wiring information for the P77 Series Pressure Controls for Low Pressure Applications. See Figure 2 and Table 2 for wiring information for the P77 Series Controls for High Pressure Applications. See Figure 3 and Table 3 for wiring information for the P78 Series Controls for Dual Pressure Applications.

Figure 1. P77 Low Pressure Control switch wiring (SPDT)

Table 1. P77 Low Pressure Control, low events, and high events
Switch and action Low event on pressure drop High event on pressure rise
SPDT A to C opens; cut-out at low event

A to B closes; cut-in at low event

 A to C closes; cut-in at high event

A to B opens; cut-out at high event
Figure 2. P77 High Pressure Control switch wiring (SPDT)

Table 2. P77 High Pressure Control, low events, high events, and model type
Switch and action Low event High event Model type
SPDT A to B closes on pressure decrease

A to C opens simultaneously

 A to B opens on pressure increase

A to C closes simultaneously

 P77AAA
A to C closes on pressure decrease

A to B opens simultaneously

 A to B closes on pressure increase

A to C opens simultaneously

 P77BEA
Figure 3. P78 switch wiring

Table 3. P78 switch wiring
LP/HP Description
LP A-C opens on pressure decrease
A-B closes simultaneously
HP A-C opens on pressure increase
A-D closes simultaneously