P70, P72, and P170 Series Controls for Low Pressure Applications Installation
Instructions
1
Refer to the
for the most up-to-date version of this document.
Applications
P70, P72, and P170 Series Controls for Low Pressure
Applications provide low-side pressure control on
commercial refrigeration and air
-
conditioning
applications.
P70A and P170A type models with Single-Pole Single-
Throw (SPST) Open-Low switch action are the most
popular models and are typically used for Open-Low
operation and pump-down control. See Table 1 through
Table 4.
P70 and P170 Series control models are also available
with SPST Open-High switch action and are typically
used for capacity control. See Table 3 and Table 4.
Control models with Single-Pole Double-Throw (SPDT)
or 4-wire, 2-circuit switch action allow users to install
alarm devices or other control circuits. See Table 4.
P72 Series control models have a Double-Pole Single-
Throw (DPST) switch with load-carrying contacts that
provide direct control of 208/240 VAC single-phase
motors up to 3 hp, 480 VAC single-phase,
non-compressor motors, and 208/220 VAC 3-phase
motors up to 5 hp. See Table 4.
These controls are available in several pressure
ranges and are compatible with most common
refrigerants. They may also be used on air, water,
and other non-corrosive fluid applications.
Ammonia-compatible models are also available. See
Table 3.
The MICRO-SET® option provides fine adjustment of
the differential setting for precision pressure control of
critical low pressure applications.
Some models feature Limited Knob Adjustment, which
restricts adjustment of the pressure settings and deters
overadjustment or tampering. See
.
The Manual Reset Lockout mechanism does not allow
the control to automatically reset after the control has
Cutout, providing shutdown capability for unmonitored
equipment. See
.
NEMA 1 enclosures are standard on most models.
NEMA 3R enclosures are available on select models.
Table 1 through Table 4 list the standard models and
features of P70, P72, and P170 controls for low
pressure applications. These standard models are
available through most authorized
Johnson Controls/PENN® distributors.
IMPORTANT:
Use this P70, P72, or P170 Series
Control for Low Pressure Applications only as an
operating control. Where failure or malfunction of the
P70, P72, or P170 Series Control could lead to
personal injury or property damage to the controlled
equipment or other property, additional precautions
must be designed into the control system.
Incorporate and maintain other devices, such as
supervisory or alarm systems or safety or limit
controls, intended to warn of or protect against
failure or malfunction of the P70, P72, or P170
Series Control.
Table 1: Standard P70, P72 and P170 MICRO-SET® Control Models for Low Pressure Applications (for
Non-corrosive Refrigerants)
Model
Number
Switch Action
Range
in. Hg to psig
(kPa)
Differential
psi (kPa)
Pressure
Connection
Maximum
Overpressure
psig (kPa)
P70AB-12
SPST
Open-Low
12 in. Hg to 80 psig
(-41 to 551 kPa)
Minimum 5 (34)
Maximum 35 (241)
36 in. Cap. with
1/4 in. Flare Nut
325
(2,241)
P170AB-12
1/4 in. Male Flare
Connector
P70, P72, and P170 Series Controls for Low
Pressure Applications
Installation Instructions
Part No. 24-7664-1601, Rev. G
Issued March 2016
