Author Topic: Fluke 5440B - 1000V range broken  (Read 1395 times)

0 Members and 1 Guest are viewing this topic.

Offline e61_phil

  • Frequent Contributor
  • **
  • Posts: 885
  • Country: de
Fluke 5440B - 1000V range broken
« on: March 08, 2018, 09:46:25 am »
Hi,

the 5440B from "a friend" has a problem. It is unstable in the 1000V range.

If I select 275V it is rock stable (measured with HP 3458A). If I go to 276V (next range) the voltage begins to change in the range of a volt. If one goes higher in voltage (~700V) the 5440B sounds like an overloaded switching power supply and resets a couple of seconds later.

The HV selftest stops with „FIL B/OUT BRDS FAULT CHECK +1100V RANGE“. I doubt that this is the problem, because 275V are stable.

Does anyone know such behaviour?

Thanks
Philipp
 

Online TiN

  • Super Contributor
  • ***
  • Posts: 4228
  • Country: us
  • xDevs.com/live - 24/7 lab feed
    • xDevs.com
Re: Fluke 5440B - 1000V range broken
« Reply #1 on: March 08, 2018, 11:45:40 am »
Quote
I doubt that this is the problem, because 275V are stable.
Maybe Fluke knows better?
I'm not familiar with 5440B, but in 57x0A PA in 220V range using another set supply rails (+/-250V) instead of high voltage, to limit the thermal dissipation. After all these calibrators are linear devices, so heat is an issue. If 5440 use same idea, than kV range would be powered from other rails than lower range.
YouTube | Metrology IRC Chat room | Live-cam | Share T&M documentation? Upload! No MB limit, firmwares, photos.
 

Offline e61_phil

  • Frequent Contributor
  • **
  • Posts: 885
  • Country: de
Re: Fluke 5440B - 1000V range broken
« Reply #2 on: March 08, 2018, 02:42:55 pm »
In the 5440B there is only a +/-30V and all the rest comes from the controlled HV transformer.
 

Online TiN

  • Super Contributor
  • ***
  • Posts: 4228
  • Country: us
  • xDevs.com/live - 24/7 lab feed
    • xDevs.com
Re: Fluke 5440B - 1000V range broken
« Reply #3 on: March 08, 2018, 05:02:23 pm »
Ok, my bad then. Check if high voltage generated properly.
YouTube | Metrology IRC Chat room | Live-cam | Share T&M documentation? Upload! No MB limit, firmwares, photos.
 

Offline RobK_NL

  • Frequent Contributor
  • **
  • Posts: 250
  • Country: nl
Re: Fluke 5440B - 1000V range broken
« Reply #4 on: March 08, 2018, 09:44:40 pm »
the controlled HV transformer.
And there's the crux. The +/- HV rails are controlled by a bunch of triacs to suit different ranges of output voltage. Guess which part of the control circuitry is malfunctioning in your friend's 5440?

The service manual has all the info needed.
Tell us what problem you want to solve, not what solution you're having problems with
 
The following users thanked this post: e61_phil, denimdragon


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf