Pressure Connections - Johnson Controls P70 Manual

M
ounting
Mount the control in an accessible position, where the
control and pressure connection line will not be subject
to damage.
!
CAUTION: Equipment Damage Hazard.
Mount the pressure control
upright and level. Position the
pressure connection line to
allow drainage away from
control bellows. Pressure tap
points must be located on the
top side of the refrigerant lines.
This reduces the possibility of
oil, liquids, or sediment
accumulating in the pressure
connection line or control
bellows, which could cause
control malfunction.
Controls with NEMA 1 enclosures may be mounted on
flat, horizontal or vertical surfaces.
Use two screws or bolts through the two outer holes
on the back of the control case when mounting control
directly to a flat vertical surface.
Use the two inner holes with the Universal Mounting
Bracket (and screws supplied) when mounting the
control to a flat horizontal surface.
IMPORTANT: Use only the mounting screws
provided with the Universal
Mounting Bracket to avoid
damaging internal components.
Do not warp control case when
mounting control to uneven
surface.
Controls with NEMA 3R enclosures are designed to be
mounted in a level, upright position with the sensing
element and conduit connection facing down. All
gaskets must be in place. Mounting NEMA 3R
enclosures in any position other than upright and level
may trap water in the enclosure and submerge internal
control components.
4 P—P70, P72, and P170 Controls for Low Pressure Applications Product/Technical Bulletin
Use mounting screws
provided. Longer screws
may damage control.
Mount bracket to
horizontal surface.
Figure 4: Mounting the P70, P72, and P170 Low
Pressure Control with NEMA 1 Enclosure
P
ressure Connections
P70, P72, and P170 low pressure controls are
connected to the controlled equipment by a capillary or
flexible hose (except ammonia models). Controls are
available with a variety of pressure connection styles.
See Figure 11 for pressure connection styles.
Follow these guidelines when installing pressure
connection lines.
IMPORTANT: If these controls are installed on
equipment that contain
hazardous or regulated
materials, such as refrigerants or
lubricants, the installer and user
should observe all regulations
governing the handling and
containment of those materials.
Avoid Sharp Bends in the Capillary Tube
Sharp bends can weaken or kink capillary tubes, which
may result in leaks or restrictions.
Allow for Slack in the Capillary Tube
Leaving a little slack in the capillary tube helps
dampen mechanical vibration that can weaken or
damage capillary tubes.
Coil and Secure Excess Capillary Tubing
Carefully loop any excess capillary tubing into smooth,
circular coils (approximately 3 in. diameter). Securely
fasten the coiled tubing.
Mounting Holes for
Flat Vertical Surfaces
Universal Mounting
Bracket
(Part No. 271-51)