Applications - PENN Controls - LIT-12012399 - P77AAA - P77BCA - P77BEA - P78LCA - P78MCA - Electromechanical Pressure Control - P77 Single Pressure Control - P78 Dual Pressure Control

P77 and P78 Series Controls for Single and Dual Pressure Applications Product Bulletin
Brand
PENN Controls
Product name
P77 Single Pressure Control
P78 Dual Pressure Control
Document type
Product Bulletin
Document number
LIT-12012399
Revision date
2020-10-28
Language
English

P77 and P78 Series Controls provide both high and low pressure control on commercial refrigeration and air-conditioning applications.

Important: Use this P77 or P78 Series Control only as an operating control. Where failure or malfunction of the P77 or P78 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 P77 or P78 Control.
Important : Utiliser ce P77 or P78 Series Control uniquement en tant que dispositif de contrôle de fonctionnement. Lorsqu'une défaillance ou un dysfonctionnement du P77 or P78 Control 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 P77 or P78 Control.

These controls are available in several pressure ranges and are compatible with most common non-corrosive refrigerants. Type 1 enclosures are standard on these models.

P77 and P78 Series Control models are typically used for high or low pressure cut-out applications, condenser fan cycling, and pump-down control. SPDT switches allow you to install alarm devices or other control circuits.

Low-pressure P77BCA Type, high-pressure P77BEA Type, and dual-pressure P78MCA Type models with Manual Reset Lockout lock out when the cut-out pressure is reached and do not automatically reset when the pressure changes after cut-out, providing shutdown capability for unmonitored equipment.

Table 2 lists the standard models and features of P77 Series Controls for low pressure applications. Table 3 lists the standard models and features of P77 Controls for high pressure applications. Table 4 lists the standard models and features of P78 Series Controls for dual pressure applications. These standard models are available through most authorized Johnson Controls/PENN® distributors.