Just FYI for many cases, heavy electric motors you leave running same as a diesel. The inrush on them is massive and is often charged separately as peak ‘demand’, the costs of which can dwarf the pure kilowatt hour charges of running the motor (the kind which most residential users are used to).
Switching large currents also will wear the components, they have limited a cycle life, so leads to expensive replacement and downtime.
Places I have worked would chew you out if you turned something off that was coming back on within an hour.
Large motors will also likely be 3 phase, which greatly limits locations they can be used.
That used to be true, but these days, electric motors all have variable-speed drives using modern power semiconductors. Anybody still using electric motors like you’re describing is running obsolete equipment.
While lots of hobbyists use VSDs on their equipment so they can run 3 phase motors off standard US line voltage (I do this for my 1/2hp CNC spindle, 1 1/2hp bandsaw in the past), these are mostly non-certified and small Chinese VSDs, that require programming and knowledge beyond the scope of what even skilled operators are normally capable of, yet alone allowed to do in electrical regulations.
The reality is a certified piece of equipment, professionally installed, can cost in the $500/horsepower range. On even a fairly modest piece of equipment with say 5x 3hp motors, that starts to become quite large percent of the cost of the equipment tacked on, and a huge amount of added complexity. The cost of these drives does not scale linearly with size.
The only motors I have used in a professional setting with a VSD required very precise speed control (spindles), not heavy equipment.
I’m sure you can find companies charging that much, but...for example, wind turbines use variable-speed motors, and those are more like $70/hp including the drivers. Electric cars use variable-speed motors, look at how much those motors cost. It’s not $500/hp, that’s for sure. A Tesla Model 3 doesn’t have $140k worth of electric motors in it, does it?
Tesla motors would not be rated at a tesla vehicles rated hp for an industrial application, they are not expected to operate at 100% duty cycle.
If you want to look at industrial motors for sale at a gold standard place like Grainger, a 250hp (sticker hp Model 3 equivalent) motor is $30,000 - $40,000 just for the motor, no VFD, no mounting, no installation.
Just the power cable that you need for a 400A 3 phase service might run something like $40-50/foot on the floor? It is so expensive you can’t even get a good reference on Google. Have to hope you have 3 phase available at all, and that you are close to the pole. A housing site with an excavator you might want 300′? 500′? Another $12,000 - $20,000
So far it is at $67,000 - $90,000 just sitting on the floor, and you need to be highly certified to touch any of those things in a commercial settings.
Edit: Just to add, the above motor weights 3000lb and uses something like 130kw/hour, so even a Tesla 3 battery would last approximately 30 minutes.
You’re using Grainger list prices? Seriously? If you actually dealt with buying stuff for industry, you’d know that their prices are much lower when you have a big account with them, and that there are cheaper options.
Grainger is the first thing that came to mind as a legitimate reference that has pricing online.
I don’t think you have invalidated any of my points, that the hp of a tesla motor doesn’t make any sense to compare with hp ratings of an excavator motor, that high hp electric powerplants are very expensive, that adding VFD’s which are not operationally necessary is a large cost and is most often left off in favor of running the motors.
Just FYI for many cases, heavy electric motors you leave running same as a diesel. The inrush on them is massive and is often charged separately as peak ‘demand’, the costs of which can dwarf the pure kilowatt hour charges of running the motor (the kind which most residential users are used to).
Switching large currents also will wear the components, they have limited a cycle life, so leads to expensive replacement and downtime.
Places I have worked would chew you out if you turned something off that was coming back on within an hour.
Large motors will also likely be 3 phase, which greatly limits locations they can be used.
That used to be true, but these days, electric motors all have variable-speed drives using modern power semiconductors. Anybody still using electric motors like you’re describing is running obsolete equipment.
While lots of hobbyists use VSDs on their equipment so they can run 3 phase motors off standard US line voltage (I do this for my 1/2hp CNC spindle, 1 1/2hp bandsaw in the past), these are mostly non-certified and small Chinese VSDs, that require programming and knowledge beyond the scope of what even skilled operators are normally capable of, yet alone allowed to do in electrical regulations.
The reality is a certified piece of equipment, professionally installed, can cost in the $500/horsepower range. On even a fairly modest piece of equipment with say 5x 3hp motors, that starts to become quite large percent of the cost of the equipment tacked on, and a huge amount of added complexity. The cost of these drives does not scale linearly with size.
The only motors I have used in a professional setting with a VSD required very precise speed control (spindles), not heavy equipment.
I’m sure you can find companies charging that much, but...for example, wind turbines use variable-speed motors, and those are more like $70/hp including the drivers. Electric cars use variable-speed motors, look at how much those motors cost. It’s not $500/hp, that’s for sure. A Tesla Model 3 doesn’t have $140k worth of electric motors in it, does it?
Tesla motors would not be rated at a tesla vehicles rated hp for an industrial application, they are not expected to operate at 100% duty cycle.
If you want to look at industrial motors for sale at a gold standard place like Grainger, a 250hp (sticker hp Model 3 equivalent) motor is $30,000 - $40,000 just for the motor, no VFD, no mounting, no installation.
https://www.grainger.com/category/motors/ac-motors/definite-purpose-motors?attrs=HP%7C250&filters=attrs
Another $15,000 - $30,000 for the VFD
https://www.grainger.com/search/motors/motor-drives-speed-controls/variable-frequency-drives-accessories/variable-frequency-drives?attrs=Maximum+Output+Power%7C250+hp&filters=attrs&searchQuery=VFD&sst=4&tv_optin=true
Just the power cable that you need for a 400A 3 phase service might run something like $40-50/foot on the floor? It is so expensive you can’t even get a good reference on Google. Have to hope you have 3 phase available at all, and that you are close to the pole. A housing site with an excavator you might want 300′? 500′? Another $12,000 - $20,000
So far it is at $67,000 - $90,000 just sitting on the floor, and you need to be highly certified to touch any of those things in a commercial settings.
Edit: Just to add, the above motor weights 3000lb and uses something like 130kw/hour, so even a Tesla 3 battery would last approximately 30 minutes.
You’re using Grainger list prices? Seriously? If you actually dealt with buying stuff for industry, you’d know that their prices are much lower when you have a big account with them, and that there are cheaper options.
Grainger is the first thing that came to mind as a legitimate reference that has pricing online.
I don’t think you have invalidated any of my points, that the hp of a tesla motor doesn’t make any sense to compare with hp ratings of an excavator motor, that high hp electric powerplants are very expensive, that adding VFD’s which are not operationally necessary is a large cost and is most often left off in favor of running the motors.