Method of operating a transport refrigeration unit
US5123252A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 11, 1991 |
| Grant date | Jun 23, 1992 |
| Priority date | — |
| Expiry date | Jul 11, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B2219/23428
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A method of operating a transport refrigeration unit with microprocessor based control. The microprocessor automatically selects an operative control algorithm, according to system configuration, with each algorithm having one or more operating conditions. Return air and discharge air temperature sensors provide inputs to the microprocessor. First, second and third sets of look-up tables are accessed by the microprocessor to determine which conditions are in the selected algorithm, and the high and low trip points of each condition. The first set of tables is accessed when the return air sensor is functional, the second set is accessed when the discharge air sensor is functional and the discharge air sensor is not, and the third set is accessed when both the return air and the discharge air sensors are not functional and the conditioned load is frozen. Failure of both sensors when the load is fresh shuts the unit down.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.