User Guide

2 P
—P100 Series Encapsulated Pressure Controls Product/Technical Bulletin
O
verview and Application
The P100 Series Encapsulated Pressure Controls are
designed for economical, compact, direct-mount,
On/Off pressure control in refrigeration and air
conditioning applications, and are compatible with all
common non-corrosive refrigerants. P100 controls
may also be used for other non-corrosive fluid
applications.
IMPORTANT: Except for those models listed as
Refrigeration Pressure Limiting
Controls
, the P100 series
pressure controls are intended to
control equipment under normal
operating conditions. Where
failure or malfunction of a P100
pressure control could lead to an
abnormal operating condition that
could cause personal injury or
damage to the equipment or
other property, other devices
(limit or safety controls) or
systems (alarm or supervisory
systems) intended to warn of or
protect against failure or
malfunction of the P100 pressure
control must be incorporated into
and maintained as part of the
control system.
Standard P100 controls are available in a variety of
factory set, non-adjustable pressure setpoints. (See
Table 1.) Non-standard models with customer
specified setpoints are available in quantity orders
only. (See
Ordering Information
.)
Some P100 control models are available with
environmentally sealed electrical contacts, suitable for
use in a wide range of ambient conditions.
Standard P100 controls feature Single-Pole,
Single-Throw (SPST) electrical switches.
•
P100A
type controls feature SPST open-low
switch action and automatic reset, and are
typically used for low-pressure cut-out and
condenser fan cycling applications.
•
P100C
type controls feature SPST open-high
switch action and automatic reset and are typically
used for high-pressure cut-out applications.
•
P100D
type controls feature SPST open-high
switch action and a manual-reset lockout
mechanism for high-pressure lockout applications.
P100E
type controls are non-standard models that
feature a Single-Pole, Double-Throw (SPDT) switch.
Standard P100 control models are supplied with 48 in.
wire leads. Some standard models have a conduit
clamp for 3/8 in. flexible metal conduit or conduit box
with an opening for a 1/2 in. conduit connector. (See
Figure 1 and Table 1.)
Standard P100 controls are available with standard
electrical duty ratings. P100 controls with heavy duty
electrical ratings are available in quantity orders. (See
Electrical Ratings
and
Ordering Information
.)
Standard P100 controls have a 1/4 in. SAE brass
female flare fitting with an internal Schrader Valve
depressor. A variety of other pressure connection
styles are available on non-standard models, in
quantity orders, including 2 in. long, 1/4 in. diameter,
copper-clad steel Thermal Isolation Fittings (TIFs).
(See Figure 5,
Dimensions,
and
Ordering Information
.)
Non-standard models are also available with 1/4 in.
male quick-connect spade terminals, wire leads of
various lengths, and wire leads with 1/4 in. male or
female quick-connect terminals. (See Figures 2 and 5,
Dimensions,
and
Ordering Information
.)
O
peration
The P100 controls are snap-acting diaphragm
pressure controls that respond to system pressure
changes at specified non-adjustable, factory-calibrated
setpoints.
A bowed, stainless steel, snap-acting disc reverses its
curvature when pressurized to the specified actuation
setpoint. When the disc snaps, it drives a set of
electrical contacts open or closed, depending on the
controls switch action.
When the applied pressure returns to the specified
deactuation setpoint on
automatic reset controls
, the
snap-acting disc and electrical contacts reset to their
original position.
On high-pressure
manual reset controls
the disc
remains in the reversed curvature position until the
deactuation pressure is reached,
and
the manual reset
button is pushed; returning the disc to its original
position and closing the electrical contacts.
A “trip free” internal latching mechanism on manual
reset controls does not allow the control to be reset
until the system pressure reaches the specified
deactuation setpoint, even if the reset button is held
fully depressed.