Replacement Motor

[StevieTT]

Hi all, new on the site and already I'm asking a question!

I work offshore and we are trying to order a new blower motor for one of our mud pumps. The old motor details are as follows:

MOTOR ELECTRIC,MODEL # G9918 LA,FRAME 215Z DELCO 460V 60HZ 3500 RPM,3 PHASE 7.5 HP 8.5 AMP

The supplier cannot supply this, no longer avaiable, but has offered two alternatives:

WEG 00736XP3E213T, 7.5hp 3600rpm 213T frame.

WEG 01036XP3E215T, 10hp 3600rpm 215T frame.

The voltage and frequency are the same.

Which should we order?

 

[jraef]

Well I for one would order neither, I personally think WEG motors are junk, but that's just a personal preference.

The only dimensional difference between the 2 is the length of the motor (the 2F dimension), but the "Z" on the old motor frame designation may also have meant a non-standard shaft size. Check that out carefully. Machining your pump can get very spendy and tricky. It may also just be that the old one is a 7.5HP (which would normally be a 213T) in a 215T frame dimension (which would normally be for a 10HP) in order to accommodate an OEM who offered both ratings but only wanted to have one mounting system.

The HP difference is somewhat significant as well, but more than necessary will always work, it just may mean getting new control equipment, wire, etc. However, if they are suggesting you look at the 10HP, they may know something they aren't divulging; maybe that the 7.5HP WEG motor is not going to provide as much torque as the one it is replacing. I would ask them to provide you with a TORQUE spec (since you already know the speed) and then take that, along with your shaft dimension and mounting specs, to a good motor supplier.

 

[itsmoked]

Giggle.. I thought of you when I read the OP Jeff.

WEG is like a mold spreading through everything.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[electricpete]

I haven't read the previous posts carefully, but I think I would look closely at the 10HP motor and see if the frame size matches. I see you wrote 215Z but I'm not sure what that means. Does the old one have a frame size marked on the nameplate like 215T ?

=====================================
Eng-tips forums: The best place on the web for engineering discussions.

 

[ScumPunk]

Hi, all
Don't know if it is the same for the original motor, but Siemens motor plates have a "Z" at the end to indicate a non-standard motor. The problem is, it could be anything from a KTY temperature sensor fitted, to a fancy paint job, and anything in between....
P.S. I take it frame size 215 refers to the shaft height? It sounds a bit big for a 7.5HP motor?
Cheers,
Martin

Apologies for repeating old news. My next post will be on the subject of old ladies sucking eggs..

 

[waross]

Hi Folks;
I would take the 215Z frame size as an old NEMA frame number.
The NEMA frame sizes were replaced by the U frame sizes many many years ago. The U frame designations were replaced by the T frame designations many years ago.
Motors of the same type, such as Totally Enclosed Fan Cooled have almost twice the horsepower rating in a "T" frame as in an old "NEMA" frame motor.
Some differences;
Many old timers considered the NEMA frame and "U" frame motors to be more robust than the "T" frame motors.
The "T" frame motors have a much shorter allowable locked rotor time to failure than the older motors.
The older motors have more breakaway torque. Good for sawmill conveyors but probablly not an issue with a fan.
It is my understanding that "Z" indicates Non-standard in all designations. Usually an extended and/or threaded shaft for a fan or pump.
If the older motor ran at much less than 100% load I would use the same horsepower as original.
If the older motor ran right at rated horsepower you may consider going to the larger motor.
Consider new protection relays. The "T" frame motors are much less forgiving than the "U" frame motors, and the NEMA frame motors were as rugged as a hammer compared to "T" frame motors.
respectfully

 

[jraef]

There is no substitute for experience...

 

[waross]

Thanks jraef;
The experience I was really impressed with was your solution to the problem in:
Synchronous compressor motor fails to get up to speed
thread237-172728
Yours
Bill

 

[StevieTT]

Thanks everyone for the information. I have learned a lot in a short time. We are going with the 215Z frame size and will adjust overloads accordingly.

Good to be part of this community and I'm sure my education will continue.:-D

 

[jraef]

waross,
I wonder if that guy ever found his problem? It's a pity when they don't let us know. I still think the rotation was his issue. I had forgotten that whole episode.

Keith,

Giggle.. I thought of you when I read the OP Jeff.

WEG is like a mold spreading through everything.

I shouldn't be so harsh, one never knows where next year's paycheck will come from! I used to badmouth my current employer, even wrote papers deriding some of their products. Had to eat those words, it took a lot of ketchup.

 

[itsmoked]

What doesn't kill you makes you stronger...

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[oftenlost]

I am sorry that I did not provide feedback on the synchronous motor which would not come up to speed. I appreciated jraef's insight and experience and thought that his input was invaluable. It did not work in this instance and,as the motor and compressor were removed, I did not have enough information to provide enough meaningful data to be of use. I believe that the advice was good and not originally on my radar scope and saw no reason to expound on the problem as I had no new data except that the local "practitioners" had deemed it in their best interest to reject the problematic compressor.

 

[MotoDrv]

Interesting that an employee of Siemens Energy and Automation is blasting a direct competitor....Hmmmm
215Z
Baldor makes a true 215 not a T not a U but a 215
the 215 is a smaller overall shaft. Go to the Baldor site and you can find drawings for both styles.
the problem is the Z - it indicates something is not standard ie Shaft dims, taper, threads or anything else a vendor wants to make difficult.
I assume by offshore you are on a platform?? That would explain why WEG is offering the XP version (explosion proof).
Is the OEM offering the WEG replacement? Doesn't appear to be the case but worth asking.
As far as XP motors WEG is very good...actually they are very good across the board despite what our resident Siemens rep might offer
if you can get any shaft details off the existing motor that would be step 1 and may direct you to the Baldor XP motor versus the WEG. Also if you have any mods that need to be done make sure it is done in a shop that is UL approved for XP motors.
Lastly given off shore make sure the paint is designed to protect against salt spray which a lot of standard paint jobs do not....

 

[143h]

Is it true that AE180M/D180M is not available in the
2 pole speed ranges? This is because I am looking for
an a flameproof AE180M,550Vac/50Hz/3 phase,18.5Kw/25hp,24.6amps to drive pitch tar.