Electrical advice needed

[buickanddeere]

25FLA motor which is different than the 30FLA we had been led to believe.
Yes the " reset" is the thermal overloads. It is not a "breaker".
32.0 amp minimum capacity cable. 32 amp thermals. 80amp fast blow fuses, 50amp D Time delay fuses or a 60amp breaker. A 30amp plug and receptacle is barely legal but is close enough to being acceptable.

 

[GregbkH]

Greg, Assuming OP does what you say, what about the plug/receptacle?
Do you know of anything in the Code that says you can't put a 30 amp receptacle on a 60 amp circuit?
On one hand, anything with a 30 amp plug shouldn't draw more than 30 amps (or hopefully 24 amps),
...On the other hand, it doesn't feel right, but I can't find anything explicit in the code that says you can't.

If using a plug and receptacle, I would use a 60 amp, three wire plug and receptacle ( 4- wire if required).

As I said before, motor circuits have their own rules. Conductor size = 125% of table 430.248 amperage for a 5 hp motor. Circuit breaker size = a maximum of 250% of table 430.248 amperage.

Therefore, conductors would #8 awg and breaker could be 70 amp. However, a 60 amp CB will work fine with the 60 amp plug and receptacle.

Overloads are between 115% and 140% of the NAME PLATE amperage on the motor, depending on the specs of the motor. Article 430.32.

Overloads in many instances are internal to the motor or in the control cabinet on the machine. If not, you must supply them yourself. I have run some of my woodworking machines through manual starters with overloads.

I know it doesn't sound right to put a 60 amp breaker on #8 conductors but it is code legal for motors.

The CB protects the conductors and the overloads protects the motor (equipment).

Always remember: The green wire is the most important wire! It can save your life.

For reference.... I am a Master Electrician.

 

[SPYDERLK]

If using a plug and receptacle, I would use a 60 amp, three wire plug and receptacle ( 4- wire if required).

As I said before, motor circuits have their own rules. Conductor size = 125% of table 430.248 amperage for a 5 hp motor. Circuit breaker size = a maximum of 250% of table 430.248 amperage.

Therefore, conductors would #8 awg and breaker could be 70 amp. However, a 60 amp CB will work fine with the 60 amp plug and receptacle.

Overloads are between 115% and 140% of the NAME PLATE amperage on the motor, depending on the specs of the motor. Article 430.32.

Overloads in many instances are internal to the motor or in the control cabinet on the machine. If not, you must supply them yourself. I have run some of my woodworking machines through manual starters with overloads.

I know it doesn't sound right to put a 60 amp breaker on #8 conductors but it is code legal for motors.

The CB protects the conductors and the overloads protects the motor (equipment).

Always remember: The green wire is the most important wire! It can save your life.

For reference.... I am a Master Electrician.

Yes, it doesnt. I know a 50A Cutler Hammer 2 pole breaker held for more than a minute at 70A as I tested the max short circuit current of my buzzbox welder and never tripped. ... And that a 30A will stand up for the measured 125A locked rotor inrush of starting a true 5HP Kellogg American compressor, and then run that compressor from 140 to 160 PSI all day long. -- That is kinda pushing it with the 30A ...

,,,,,,,,,,But in general Im with teejk on this v V v

Well...if you have a well known manufacturer and they lay out the requirements (surely passed by their engineers and legal departments), why argue with them? As for the National Electric Code, it is becoming a joke in too many ways...the basic principles have not changed since before Edison. I find the biggest objectors to "DIY" electrical are those that object to people figuring out that most things don't require a professional. I hired one on this house and spent a lot of time fixing his screw-ups (some that will never get fixed without tearing out drywall and doing it right). Guessing you are in that camp.

 

[dadster4]

The 5 HP motor in the shaper is rated at 14 amps per the specs in the owners manual. 30 amp FLA will rarely be reached on a shaper this size and only momentarily if it does, anyone who has used woodworking equipment of this size or larger would know this. The recommended breaker, outlet, and wire size are more than adequate. The motor control on this shaper is a simple start/stop switch with reversing capability. Thermal protection is an internal motor protection circuit to prevent overheating and damaging the motor windings. Overloads/heaters are external to the motor (not included in this shaper's controls) to protect the wiring if an overload or over-temp condition exists. The circuit breaker protects the wiring in drastic overload/shorted/grounded situation.
So follow the manufacturer's recommendations and you will be safe. Nice shaper by the way, serious piece of woodworking machinery, new kitchen cabinets in the future?

 

[SPYDERLK]

Greg is correct. The manual says 5 hp motor will draw ~25 amps, which makes a 30 amp circuit too small. Code (table 430.248) says it will draw 28 amps, and you must size circuit based on this, which also makes a 30 amp circuit too small.
Will a 30 amp circuit work?: Most of the time.
Will it be safe: Yes, even if it does trip out occasionally.
Will it be to Code? The answer is obvious, but let's pretend it falls under Article 90.4: "...the authority having jurisdiction (AHJ) may waive specific requirements..."

In spec/data section the manual calls out 14A rating for the motor, which of course makes the 5HP BS. The 30A circuit will be ample for that overloaded 2HP motor.

 

[GMIslander]

This is the spec sheet for the equipment, why not follow it?
Electrical:
Power Requirement........................................................................................................... 220V, Single-Phase, 60 Hz
Prewired Voltage.................................................................................................................................................. 220V
Full-Load Current Rating........................................................................................................................................ 25A
Minimum Circuit Size.............................................................................................................................................. 30A
Connection Type....................................................................................................................................... Cord & Plug
Power Cord Included............................................................................................................................................... No
Recommended Power Cord............................................................................... “S”-Type, 4-Wire, 10 AWG, 300 VAC
Recommended Plug Type................................................................................................................................. L15-30
Switch Type............................................................................................ Control Panel w/Magnetic Switch Protection

 

[GregbkH]

Yes, it doesnt. I know a 50A Cutler Hammer 2 pole breaker held for more than a minute at 70A as I tested the max short circuit current of my buzzbox welder and never tripped. ... And that a 30A will stand up for the measured 125A locked rotor inrush of starting a true 5HP Kellogg American compressor, and then run that compressor from 140 to 160 PSI all day long. -- That is kinda pushing it with the 30A ...

,,,,,,,,,,But in general Im with teejk on this v V v

I'm only stating what is code legal..... which , by the way, most communities and insurance companies want you to comply.

The system I described is code legal and bullet proof. It will work without a hitch. Plus, It covers my ***** if I were to install it so I wouldn't be sued.

You or any other arm chair electrician are free to do what you feel is right. It helps with my job security.

Thanks

 

[CobyRupert]

In spec/data section the manual calls out 14A rating for the motor, which of course makes the 5HP BS. The 30A circuit will be ample for that overloaded 2HP motor.

Ahaa! Good catch.
Physically impossible for a 220v motor drawing 14 amps to put out anything over 4 hp.
Earlier, manual say it draws 25 amps, but specs say 5 hp, 14 amps !!
Like I said, I've seen very little in this manual that tells me they know what they're doing.
If it really is a 14 FLA motor, then a 30 amp circuit is fine. If it really is a 5 hp motor, a bigger circuit would be required.

 

[SPYDERLK]

Ahaa! Good catch.
Physically impossible for a 220v motor drawing 14 amps to put out anything over 4 hp.
Earlier, manual say it draws 25 amps, but specs say 5 hp, 14 amps !!
Like I said, I've seen very little in this manual that tells me they know what they're doing.
If it really is a 14 FLA motor, then a 30 amp circuit is fine. If it really is a 5 hp motor, a bigger circuit would be required.

Ah yes. That would be a cryogenic/superconducting motor with air bearings, running in a vacuum ... briefly.

 

[dadster4]

Yes, the spec sheet is messed up... most likely a misprint. I figure they meant to say 24 amp motor rating.
The recommended breaker is marginal at this level... a 40 amp would be better.