INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Member Login




Remember Me
Forgot Password?
Join Us!

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

Join Eng-Tips
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.
Jobs from Indeed

Link To This Forum!

Partner Button
Add Stickiness To Your Site By Linking To This Professionally Managed Technical Forum.
Just copy and paste the
code below into your site.

Compressor high ampere

Compressor high ampere

(OP)
We are trying to troubleshoot a refrigeration system running on freon 12. The reciprocating compressor trips off during 30 mins of run. The comressor motor and mechanical system is newlyh reconditioned and tested before installation. What could be the possible causes and your recommendations. Thanks

RE: Compressor high ampere

Check the rated current. Measure the current during the 30 minute run and if it exceeds the rated, you have a compressor problem which can range from bad bearings to excessive pressures. If the rated current is less than rated and the circuit breaker is the one specified by the unit, then it is possible that the breaker is faulty.

RE: Compressor high ampere

Single phase?  Three phase?

Trips on what?  External breaker, external thermal?  Internal thermal?

RE: Compressor high ampere

Check the system as a whole.  High condenser pressures ?  Is the condenser coil (if it's an air-cooled unit) choked ?  

HVAC68

RE: Compressor high ampere

(OP)
Its 3-phase, trips on external breaker. Thanks

RE: Compressor high ampere

We're talking breaker not thermal overload here? If the breaker is tripping as soon as the machine attempts to start then it is probably tripping on the 'magnetic' or instantaneous element. Usually this is adjustable to accomodate the starting current drawn by the motor, typically 6 - 8 times full load current but not always. It might be indirectly quoted on the nameplate as a NEMA code, e.g. Design B, Design C, etc. This letters equate to multiples of running current.

Sometimes breakers get tired and the mag trip gets trigger-happy. Other times they are just set wrongly. Can you post some details of the breaker type, rating and settings, and also any data from the motor nameplate? At present there are too many unknowns to provide any sensible direction.

----------------------------------
  Sometimes I only open my mouth to swap feet...

RE: Compressor high ampere

Similer situation with a heat pumpin cooling mode amp reading kept going up tillthe breaker tripped. The system was grossly overcharged.

RE: Compressor high ampere

cabalen (Mechanical)
Have you put a set of gauges on this system and checked the head pressure?
 Until this crew knows  the head pressures are normal, they cannot give you a definitive answer, any thing else is speculation.
B.E.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close