Penn P77XAAW Installation Manual

P77 Series Controls for Low Pressure and Hazardous
Location Applications
Installation Guide
P77XAAW
Applications
P77 Series Controls for Low Pressure and Hazardous Location Applications provide low pressure control using a
low energy signal from inside an explosive zone on commercial refrigeration and air-conditioning applications. The
controls have special dry circuit switches with gold-plated contacts for improved contact characteristics that are
required in circuits with low voltage and low current. In standard applications, use P77 control models for low
pressure cut-out applications and pump-down control.
IMPORTANT: Use this P77 Series Control only as an operating control. Where failure or malfunction of the 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 control.
IMPORTANT : Utiliser P77 Series Control uniquement en tant que dispositif de contrôle de fonctionnement.
Lorsqu'une défaillance ou un dysfonctionnement du contrôle risque de provoquer des blessures ou d'endommager
l'équipement contrôlé ou un autre équipement, la conception du système de contrôle doit intégrer des dispositifs de
protection supplémentaires. Veiller dans ce cas à intégrer de façon permanente d'autres dispositifs, tels que des
systèmes de supervision ou d'alarme, ou des dispositifs de sécurité ou de limitation, ayant une fonction
d'avertissement ou de protection en cas de défaillance ou de dysfonctionnement du contrôle.
These controls are available in several pressure ranges and are compatible with propane refrigerants. They are
designed to operate in
• Group II, Zone 2 environments, as defined in the ATEX Directive and UKEx regulations.
• Class I, Division 2, Group D environments, as defined in NFPA 70 and CSA C22.2.
They are equipped with a 6 mm outer diameter copper tube. An adjustment lock plate is included with these
models.
IP54 enclosures are standard on these models.
Single-Pole, Double-Throw (SPDT) switches allow you to install alarm devices or other control circuits (see
Table 1). Automatic reset P77XAAW type models can also be wired for low-pressure cut-in operation.
Table 1 lists the standard models and features of P77 controls for low pressure and hazardous location
applications. These standard models are available through most authorized Johnson Controls®/Penn distributors.
Table 1: Standard P77 model for low pressure applications, for non-corrosive refrigerants)
Model number Pack type
P77XAAW-18000C
Individual pack
Switch action
SPDT
(see Figure 4
and Table 2)
P77 Series Controls for Low Pressure and Hazardous Location
Applications Installation Guide
Range, Differential,
barg (psig) bar (psi)
-0.5 to 7 0.6 to 3
(-7.25 to 102) (9 to 44)
1
Part No. 24-7664-3213, Rev. D
Issued September 2024
Pressure Maximum
connection bellows
pressure,
barg (psig)
6 mm 22 (319)
diameter
copper tube