The A/E 32C-45A (Figure 1) is a lightweight, self-contained unit in a weatherproof aluminum case with a built-in heat pump designed to provide a high capacity heat-cool environmental control system. The ECU will control the temperature of an adequately enclosed compartment within the variable range of 7° C to 32° C (45° F to 90° F) in ambient temperatures of -32° C to 52° C (-25° F to 125° F). The temperature is controlled by a cool-heat control thermostat. The ECU works as a heat pump in one of the three cycles; a heating cycle, a cooling cycle, or defrosting cycle.
The ECU is a vertical compact ECU with a nominal cooling capacity of 36,000 British Thermal Units per hour (BTU/hr). It has a nominal heating capacity of 77,000 BTU/hr with supplementary heaters, and 36,000 BTU/hr without supplementary heaters when supplied with a 208-VAC, 3 phase, 50/60 Hz, 3-wire power.
The supplemental heating unit is a two-stage assembly; each stage contains 6-KW heaters capable of dispersing a total of 41,000 BTU/hr. Over-heating protection is controlled by a 160° F (71° C) cutout (thermoguard) located in the return plenum over the indoor coil (See technical manual for details). The unit contains air-cooled indoor and outdoor finned tube coils.
Supplementary heating elements are protected by two fail-safe, fuse links in each stage set to open at 306° F (152° C). The first supplemental heating stage is controlled through the second stage of the indoor thermostat. The second stage of the supplemental heating is controlled by an outdoor thermostat (See technical manual for details).