]
Sent: Wednesday, August 07, 2002 11:28 AM
To: 'David Heald'; 'EMC_PSTC'
Subject: RE: Thermal breakers vs magnetic breakers for telecom
Yeah, I had used them . . . once.
As they were a lower cost circuit breaker we spec'd them into a telecom
system. What we didn't t
RE: Thermal breakers vs magnetic breakers8/7/02
David, One of the reasons they may have been rejected previously is their
change in trip point due to temperature changes. The higher the ambient
temperature gets the lower the trip point of the thermal device becomes. If
When I worked on CATV power supplies I had two reasons for using magnetic;
1. Nuisance tripping of thermal breakers during high ambient temperatures
2. Magnetic breakers often carry a higher level of safety rating (UL Listed
vs UL Recognized)than thermal and have higher short circuit maximum rat
Yeah, I had used them . . . once.
As they were a lower cost circuit breaker we spec'd them into a telecom
system. What we didn't think about was the temperature extremes.
For the higher temp tests for NEBS the higher temp breakers
were too large and too expensive - for my management anyway.
I s
Dave Heald wrote:
>> Does anyone know of any telecom (or general) reasons why thermal circuit
breakers may be unacceptable for telecom products? <<
Some thought on the matter suggests that thermal breakers may be too
variable in their trip current and time over the usual temperature range of
-4
5 matches
Mail list logo
