Heat pump control system
US4102389A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 15, 1976 |
| Grant date | Jul 25, 1978 |
| Priority date | — |
| Expiry date | Oct 15, 1996 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF25B2400/05
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
A control system for regulating operation of a heat pump includes a basic timer circuit which is utilized in different ways for different purposes. The system senses pressure across the outdoor coil, outdoor temperature, temperature in the liquid line to and from the outdoor coil, and temperature of the compressor discharge line. The control system initiates a defrost cycle for the outdoor coil responsive to a high static pressure across the outside coil, at the same time that the liquid line temperature is below a preset temperature. The defrost cycle is terminated when the liquid line temperature reaches a given temperature or when that liquid line temperature has been at a lower temperature for a certain time interval as determined by the basic timer circuit. When the compressor is shut down, the timer is also started to ensure that the compressor is not brought back on before the expiration of the basic shut-down time interval. In addition the compressor cannot be operated when the outside temperature is at or below whatever temperature is determined by the standby heat setting. The compressor likewise cannot be operated when there is a second call for defrost within a given ti…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.