Product Overview

The performance specifications are nominal and conform to acceptable industry standards. For applications at conditions beyond these specifications, consult the local Johnson Controls office.
Johnson Controls, Inc. shall not be liable for damages resulting from misapplication or misuse of its products. © 2009 Johnson Controls, Inc.
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P70, P72, and P170 Series
Controls for Dual Pressure Applications
Code No. LIT-1900172
Issued February 1, 2009
Description
The P70, P72, and P170 controls for dual
pressure applications are designed primarily
for use as combination high and low pressure
controls on commercial refrigeration and air
conditioning applications.
These controls are available in several
pressure ranges and are compatible with most
common refrigerants. Ammonia compatible
models are also available.
These controls respond directly to system
pressure changes on both high and low sides,
and can provide single-device control of the
compressor.
Controls are available in several different
electrical ratings and switch configurations,
including independent high and low pressure
switches (on P70S and P170S models). The
P72 models provide direct control of
208-240 volt, single-phase motors up to
3 horsepower, and 208-220 volt,
3-phase motors up to 5 horsepower.
Features
• all-steel case and cover built to provide
long lasting, rugged protection for internal
components
• “Sight-Set” calibrated pressure adjustment
displays a visible pressure scale, fully
adjustable through the range without
removing the cover (on NEMA 1 enclosure
models)
• MICRO-SET™ differential option allows for
precise control on low pressure
applications
• independent high and low pressure
switches (P70S and P170S Models)
satisfies a variety of dual pressure
application wiring requirements with a
single versatile control
• convertible high pressure reset–auto reset
or manual reset lockout (P70S and P170S
Models) reduces inventory— one control
can be adapted to several dual pressure
applications in the field
Applications
• P70S and P170S models have
independently operated high and low
pressure Single-Pole Double-Throw
(SPDT) switches that can be wired to
satisfy a variety of control requirements.
These adaptable controls also come with a
high pressure manual reset lockout
mechanism that may be converted to
automatic reset.
• P70L, M, N, and P170L, M, N models
have a Single-Pole Single-Throw (SPST)
switch. Models are available with
automatic or manual reset lockout options.
Models with manual reset are available
with either high-side-only manual reset, or
low-side and high-side manual reset.
Ammonia-compatible models are also
available (P70L and P70M only).
P72 models have a Double-Pole Single-
Throw (DPST) switch with load-carrying
contacts that can provide direct control of
208-240 VAC, single-phase motors up to
3 hp, and 208-220 VAC, 3-phase motors up to
5 hp. Refer to DPST Electrical Ratings (P72L,
M, and N Types) on page 3.
Some models are available with Limited
Knob Adjustment, which restricts adjustment
of the pressure settings and deters over-
adjustment or tampering.
NEMA 1 enclosures are standard on most
models. NEMA 3R enclosures are also
available.
Selection Chart for Standard Model P70, P72, and P170 Dual Pressure Controls (Part 1 of 2)
Code
Number
Switch
Action
Low Pressure Side psig (kPa) High Pressure Side psig (kPa) Pressure
Connector
Limited Knob
Adjustment
Range Differential Range Differential (Non-Adjustable)
MICRO-SET Controls for Non-Corrosive Refrigerants
P70LB-6C
1
SPST 12 in.Hg
to 80
(-41 to 552)
Min 5 (34)
Max 35 (241)
100 to 500
(690 to 3447)
Fixed Approx. 65 (448) 36 in.
Capillary with
1/4 in. Flare
Nut
Low CUT OUT
P70MA-18C
1
Lockout Requires Manual Reset None
P70SA-1C
1
Two Independent
SPDT
Fixed at 65 (448) or
Lockout Requires Manual Reset
P170LB-6C
1
SPST Fixed Approx. 65 (448) 1/4 in. Male
Flare
Connector
Low CUT OUT
P170MA-18C
1
Lockout Requires Manual Reset None
P170SA-1C
1
Two Independent
SPDT
Fixed at 65 (448) or
Lockout Requires Manual Reset
All Range Controls for Non-Corrosive Refrigerants
P70LB-1C
1
SPST 20 in.Hg
to 100
(-68 to 690)
Min 6 (41)
Max 50 (345)
100 to 500
(690 to 3447)
Fixed Approx. 65 (448) 36 in.
Capillary with
1/4 in. Flare
Nut
Low CUT OUT
P70MA-1C
1
Lockout Requires Manual Reset None
P70NA-1C Fixed (Manual
Reset)
P72LA-1C
1
DPST Min 7 (48)
Max 50 (345)
Fixed Approx. 65 (448)
P72LB-1C
1
Low CUT OUT
P72MA-1C
1
Lockout Requires Manual Reset None
P72NA-1C
1
Fixed (Manual
Reset)
P70SA-1 Dual Pressure Control