Hobart Handler 135

Reply

  #1  
Old 07-18-05, 05:20 PM
h nu
Visiting Guest
Posts: n/a
Hobart Handler 135

I have a Hobart Handler 135, which trips the breaker its on all the time. I had an electrician measure the amps it was pulling when it was at its max. The result was around 35 amps. Mind you, this is a 110v wire welder. The plug on the unit is only rated for ~25 amp use, and the specs on the unit say 20 amp input.

we mesured the amperage from the breaker box, 20 feet away, from the welder. So I think the welder really is drawing more than it should. Is this something wrong with the welder or what?
 
Sponsored Links
  #2  
Old 07-18-05, 08:08 PM
Member
Join Date: Oct 2004
Location: USA
Posts: 719
Received 0 Votes on 0 Posts
The odds are hi samething as this link.

http://forum.doityourself.com/showthread.php?t=221877

Disconnect the diodes, plug the unit in, see if it trips the breaker.

Read the Caution about the capacitor, if it has one. post # 5
 

Last edited by GWIZ; 07-18-05 at 08:18 PM.
  #3  
Old 07-20-05, 06:08 PM
h nu
Visiting Guest
Posts: n/a
i am confused at how this is related to the diodes being bad?

I should mention that the welder works, and makes good welds. Its just that after about 5 min of welding, the breaker will go out. then I flip it back and weld some more, then 2 min later it will trip. and from there on out, it will trip if I weld for more than 5-10 seconds at a time.

So while im welding, it is pulling more amps than it should (I think). It was my understanding that the diodes either work, or they don't. if they are bad, the machine would not work. but since it does...

This does however sound like a seperate issue I am having with a stick welder. the fan comes up, and it sounds like its working, but nothing comes out of the electrode. err, so where can you purchase these diodes? or is it something you need to take to a welding repair shop?
 
  #4  
Old 07-20-05, 07:11 PM
GregH's Avatar
Super Moderator
Join Date: Jan 2001
Location: Manitoba
Posts: 10,015
Received 13 Votes on 13 Posts
You may not be reading the welder's specs correctly.

Your unit is a 135 amp machine but the 20 amp draw is shown in the manual at a 90 amp output.
If you were to set your machine to give yourself a 90 amp output it would probably draw 20 amps.
The 230 volt model of your machine draws around 20 amps at 230 volts @ 130 amp output.
Using very rough numbers if you were to crank up your machine to the max it would draw around 40 amps on 120 volts.

Handler manual (pdf)
 
  #5  
Old 07-20-05, 10:17 PM
h nu
Visiting Guest
Posts: n/a
ok that makes sense. but if my machine can draw up to 35-40 amps, why is the cord on the machine only rated for 20 amps? and the plug that came with the machine is also only rated for 20 amps? why is this?
 
  #6  
Old 07-20-05, 10:55 PM
GregH's Avatar
Super Moderator
Join Date: Jan 2001
Location: Manitoba
Posts: 10,015
Received 13 Votes on 13 Posts
Two reasons:

There is an exception in most electrical codes relating to the size of breaker that feeds a welder.
You are allowed by code to fuse a circuit for a welder for a higher amperage than what conductors are normally rated at.
(The folks in the electrical forum can help with this.)

Another reason is marketing.
Mfr's are being deceitful when publishing the specs for their equipment.
They put a sticker on the side of this machine that states it is a 135 amp unit but fail to disclose the duty cycle and primary circuit amp draw.
They are making it seem like you can just take this unit out of the box, plug it in and crank it to the amperage that is printed on the side.

I think that if you take into account the fact that they rate the required fuse for a 90 amp output, you would realize the mfr is saying it's really only a 90 amp machine, not 135.
 
  #7  
Old 07-21-05, 12:15 AM
Member
Join Date: Oct 2004
Location: USA
Posts: 719
Received 0 Votes on 0 Posts
" i am confused at how this is related to the diodes being bad? "


You changed the problem on me from your first post.
From a dead short to working for 2 min and tripping a breaker.
---------------------------------------------------
First thing I would try the welder on a different 20 amp circuit.
Be sure that you do NOT have any other items in use on the same breaker.
Breakers go bad.
--------------------------------------------------
You Hobart has a built in circuit breaker, if that's not tripping I would talk to Hobart.

Your duty cycle is LESS then 10% at full power, tripping the breaker after 2 min. maybe Hobart's intent.
Your going to damage the machine going over the duty time.

If not,
I would suspect the 53,000 uf capacitor. they can get leaky/shorts.
This size capacitors have a very-very-large current draw/surge to get charged up.
You current measurements must be made after the capacitor is fully charged, that will be difficult they add bleed resistors across the Cap's for safety to discharge them.

A 35 amp input reading for your 54 Seconds of duty time maybe normal.
That may explain how they get 135 amps output from your 90 RATED welder.

? How low must you adjust the control, before the breaker stops tripping (from 1-10) ?
================================
"It was my understanding that the diodes either work, or they don't. if they are bad, the machine would not work. but since it does..."

97% open or shorted. Your right.
2% the diodes have thermal problems.
1% you never know.

Your first post did not state your machine worked.
=================================
----------------------------------------------------------------------
Is your stick welder AC/DC
I assume it has a welding transformer inside, if its an AC welder you don't have power diodes.
I would look for loose connections, bad switches then diodes. for stick welders
---------------------------------------------------------------------
"so where can you purchase these diodes? "
Depends on the part number.

http://www.mouser.com/index.cfm?handler=home

http://www.digikey.com/
---------------------------------------------------------------------
" or is it something you need to take to a welding repair shop? "

If the diodes/parts have standard mountings and part numbers you should find them.
or you can get the parts from the manufacture for 3 times the price.

Some are bolt on connections.
Some are solder in diodes.
you can ask a small TV shop to solder them for about $20.00
--------------------------------------------------------------------
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
 
Ask a Question
Question Title:
Description:
Your question will be posted in: