Recent content by jammyjim

Motors have been running for years, nothing much has changed, the load on them is pretty constant, but the last few months they have been going through brushes very quickly, really odd

https://www.dropbox.com/s/c2sotkhh1mwhizt/2014-09-12%2009.34.59.jpg?dl=0 <---- motor nameplate https://www.dropbox.com/s/siwakf3i52wnc4p/2014-09-12%2009.35.29.jpg?dl=0 <---- motor https://www.dropbox.com/s/pxtrtkym7uftq83/2014-09-12%2009.36.51.jpg?dl=0 <---- rugulator nameplate...

Thx for the replies, I'll be uploading some pics later, btw it's a Laurence Scott motor

No slip rings, and it's purely An AC machine, the sator is just a standard 3 phase winding 6.6 KV nothing complicated,the armature just looks like an armature from a DC motor visually, but I think the internal windings are very different, the brush gear has 36 brush arms each holding 5 brushes...

hi Just after some fresh ideas on this problem, got 3 of these machine running large freshwater pumps for some reason recently they are going through brushes very quickly, a new set was put in last week 144 brushes, and there already showing signs of major wear, also sparking a fair bit not...

Thx for the reply Im off work for a week so i cant answer that one yet i`ll note those figures when i get back to it. BTW i forgot to say, i have run this motor seperatly exciting the field, 150v on fiels 150 volts on armature, ran fine around 1800 rpm if i remember right, and 0.5 Amps i just...

Hi all I just need someone to confirm im doing this right, i have a simple shunt motor off load not coupled up, 230v DC 8 amps 3000 rpm, 2 leads from the field winding f1 and f2 (500 ohms) btw 2 leads from the brush boxes a1 and a2, brushes bedded in fine, commutator look good, IR readings all...

Hi Recently rewound and induction generator ( stator and rotor) with slip rings 4 pole machine, have run it as a motor by shorting out the slip rings, ran ok... Could anyone advise me on the best way to set this machine up, to see if its generating, how do drive it, how to excite it etc, any...

Thx fot that pete

Can anyone tell me if these two are the same, when flash testing a motor i would usually use twice the nameplate voltage plus 1kv and add 20%, do the same rules apply on a baker surge test?

What could be the possible causes of the following slip ring failure, the middle ring (of 3) has been getting extremely hot and fusing the brushes in thier holders, when this first happened new slip rings were made, and the brushgear was completely overhauled, the stator and rotor test ok The...

3 leads will be the motor windings the ones you said were about 0.4 ohms 1 lead will be earth 2 leads will be thermal protection either thermistors 150-160 ohms, or klixons 0.1 ohms 1 lead will probably be a moisture sensor, which should not have continuity with the earth lead, unless the...

tbh the ampmeter im using probably needs calibrating, i doubt the 1.7 amps it was showing was accurate

I did that test pete, and as you said, the polarity changed from + to - when i spun the armature in deifferent directions, fennell, ill double check everything agian monday and get back to you, thx for all the replies

yes pete the brushgear is positioned as you described, ill try the test you mentioned, if i understand you correctly ill need to supply the field only, put an avo across the two brushboxes, then spin the armature by hand in either direction, to see if the polarity changes...