Wiring - PENN Controls - A19BAC - A28AA - Electromechanical Temperature Control - A19 Coiled Bulb Control - A28 and A36 Multi‐Stage Temperature Control

A19BAC, A28AA Single and Two-Stage Space Thermostats for Heating and Ventilation Applications Installation Guide
Product name
A19 Coiled Bulb Control
A28 and A36 Multi‐Stage Temperature Control
Document type
Installation Guide
Document revision
G
Revision date
2023-10-18
Part number
996-238
WARNING
  • Risk of Electric Shock
  • Disconnect or isolate all power supplies before making electrical connections. More than one disconnection or isolation may be required to completely de-energize equipment. Contact with components carrying hazardous voltage can cause electric shock and may result in severe personal injury or death.
Avertissement
  • Risque de décharge électrique
  • Débrancher ou isoler toute alimentation avant de réaliser un branchement électrique. Plusieurs isolations et débranchements sont peut-être nécessaires pour -couper entièrement l'alimentation de l'équipement. Tout contact avec des composants conducteurs de tensions dangereuses risque d'entraîner une décharge électrique et de provoquer des blessures graves, voire mortelles.
Important: Use the supplied 8-32 x 1/4 in. binder head terminal screws. Substitution of other screws could cause problems in making correct connections.

Make all wiring to conform to local, national, and regional codes. Use copper conductors only. Do not use the temperature controls on applications where electrical ratings exceed the ratings shown on the control’s cover label.

For typical wiring applications, see the following figures:

Figure 1. A19BAC typical heating control circuit

Figure 2. A19BAC typical ventilating or cooling control circuit

Figure 3. An A19BAC in control of heating and ventilating systems

The following figure shows standard wiring for the control of a two speed ventilation fan. When control temperature reaches the dial setting, the low temperature switch starts the fan on low speed. If the space temperature continues to rise, the high temperature switch supplies power to the high speed motor winding and disconnects the low speed winding.

Figure 4. A28AA wiring for control of a two speed ventilation fan

The following figure shows standard wiring for a two speed volume fan application. The fan starts when the temperature reaches the dial setting. If the temperature continues to rise, the high temperature switch energizes the damper motor.

Figure 5. Standard wiring for a two speed volume fan application

The following figure shows standard wiring for a combination heating and cooling system with automatic changeover. When the temperature increases to the dial setting, the heating system turns off because the R-B low temperature switch contacts open. An increase of approximately 3°F (1.7°C) turns on the fan or cooling system through the R-Y contacts of the high temperature switch.

Figure 6. Standard wiring for a combination heating and cooling system with automatic changeover

The following figure shows standard wiring for two stage heating. When the temperature drops to the dial setting, the first stage heating turns on. If the temperature continues to drop by approximately 3°F (1.7°C) the second heating stage turns on.

Figure 7. Standard wiring for two stage heating