Patent · US Expired

Controller for heat engineering installations

US6507468B1 · kind B1 · utility

2Cited by

8References

15Claims

0Family size

Assignee

GESTRA AG · DE

Inventors

Juergen Klattenhoff · Delmenhorst, DE
Joachim-Christian Politt · Bremen, DE
Guenter Schmitz · Oldenburg, DE

Key dates

Filing date	Jun 27, 2000
Grant date	Jan 14, 2003
Priority date	—
Expiry date	Dec 7, 2020

Classification

Technology area (CPC F)Mechanical Engineering; Lighting; Heating
CPC primaryF22B37/46
WIPO fieldThermal processes and apparatus
WIPO sectorMechanical engineering

Abstract

A controller has two shunt lines connected in parallel with safety relays. For testing their switching capability, the safety relays are reversed to their idle positions and the change in voltage is monitored on their idle contacts. If voltage is missing, an error signal is issued. During the test, the parallel shunt line is closed so that the safety power line is not interrupted. Switching amplifiers having a response and action time which is a fraction of the preset response time of the safety relays control the safety relays. For testing the electrical control, the drives of the safety relays are switched to currentless and the change in voltage is monitored on the drives. If the change in voltage is inadequate, an error signal is issued. The safety relays remain in their operating positions during the test.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.