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-   -   Will a 1/3 horse power sump pump motor burn up at half power? (http://www.chiefdelphi.com/forums/showthread.php?t=84902)

Weird Al/ Tony 02-04-2010 15:16

Will a 1/3 horse power sump pump motor burn up at half power?
 
I am building my own battle bot and I'm working on running it off of two 12V batteries. It will be driven by two heavy sump pump motors. I will only be able to obtain a possible half power off of the batteries and I need to know if that will ruin the engines. I have been told it will by a freind but I dont beleive her. So I need some help. I dont want to waste/ruin the motors after all!

Daniel_LaFleur 02-04-2010 16:52

Re: Will a 1/3 horse power sump pump motor burn up at half power?
 
Quote:

Originally Posted by Weid Al/ Toni (Post 947150)
I am building my own battle bot and I'm working on running it off of two 12V batteries. It will be driven by two heavy sump pump motors. I will only be able to obtain a possible half power off of the batteries and I need to know if that will ruin the engines. I have been told it will by a freind but I dont beleive her. So I need some help. I dont want to waste/ruin the motors after all!

OK, There's not quite enough info here but I'll give it a try.

By "only be able to obtain a possible half power off of the batteries" do you mean that the pump is 24V and you are running it at 12V? If so, then your friend is absolutely correct. The motor will try and do the same amount of work with only 1/2 the voltage thus requireing twice (roughly) the current. This will heat the motor more.

In addition, most sump pumps are designed to work submerged in water. They use the water to cool the motor, thus will need extra cooling if it is run using air to cool it.

Stephen Kowski 02-04-2010 17:04

Re: Will a 1/3 horse power sump pump motor burn up at half power?
 
Quote:

Originally Posted by Weid Al/ Toni (Post 947150)
I am building my own battle bot and I'm working on running it off of two 12V batteries. It will be driven by two heavy sump pump motors. I will only be able to obtain a possible half power off of the batteries and I need to know if that will ruin the engines. I have been told it will by a freind but I dont beleive her. So I need some help. I dont want to waste/ruin the motors after all!

What are your loading conditions? Do you have a model number for the motor so that we might be able to better understand? Are you using the batteries that we used for competition or are these some other chemistry (NiCd, Li-ion)? are these batteries in series, parallel, or individually connected to the motors?

Why are you only able to obtain half power? How are you gearing this drive train? wheel size? wheel traction? In general, depending on the loading condition, the power your motor demands is not a static number

Will it burn up? Well that depends a lot on the motors thermal constants (casing, efficiency, etc) and it's ability to handle a stall current among other things

More information is required to give you a good answer.

Weird Al/ Tony 02-04-2010 22:53

Re: Will a 1/3 horse power sump pump motor burn up at half power?
 
when I posted this I knew nothing about the topic I was asking about. so here arwe the facts. I have a 115 A/C volt motor, I'm using a 12 D/C volt battery to power it. the motor is 5.7 amps, 60 hz, 1725 RPM, and it is non submersible. air cooled and isnt ment to be wet. I have a model #: xqj48517028j p and I ndont know what the p means. it also says it is thermally protected, single phase. what is single phase? and it is 60 cycle? what is that. fla= 5.8 sf= 1.0 and I have no clue what any of that means. help me out, thanks.:confused:

kevin.li.rit 02-04-2010 23:57

Re: Will a 1/3 horse power sump pump motor burn up at half power?
 
Quote:

Originally Posted by Weid Al/ Toni (Post 947302)
when I posted this I knew nothing about the topic I was asking about. so here arwe the facts. I have a 115 A/C volt motor, I'm using a 12 D/C volt battery to power it. the motor is 5.7 amps, 60 hz, 1725 RPM, and it is non submersible. air cooled and isnt ment to be wet. I have a model #: xqj48517028j p and I ndont know what the p means. it also says it is thermally protected, single phase. what is single phase? and it is 60 cycle? what is that. fla= 5.8 sf= 1.0 and I have no clue what any of that means. help me out, thanks.:confused:

My guess is that you won't be able to run it directly off the 12 bolt battery. It sounds like it uses the 110 volts out of your wall which is single phase. I.E. there is only one sinusoidal wave coming out of your standard wall outlet. (opposed to 3 sinusoids in 3 phased 220 volts). 60 cycle refers to the 60 hz which is the frequency of the sinusoid in your wall.

The thermal protection most likely means that the motor will stop running if it gets to hot to prevent it from damaging itself.

Weird Al/ Tony 03-04-2010 00:08

Re: Will a 1/3 horse power sump pump motor burn up at half power?
 
well what are sinusoids. and it is a wall plug type motor. so that means like even if I wanted to I couldnt convert it? and what about like wheelchair motors cause I got those. and I mean what if I used like a fan motor from a like normal around the house use post fan or whatever? would i not be able to use that with a battery. :confused:

kevin.li.rit 03-04-2010 00:14

Re: Will a 1/3 horse power sump pump motor burn up at half power?
 
Quote:

Originally Posted by Weid Al/ Toni (Post 947323)
well what are sinusoids. and it is a wall plug type motor. so that means like even if I wanted to I couldnt convert it? and what about like wheelchair motors cause I got those. and I mean what if I used like a fan motor from a like normal around the house use post fan or whatever? would i not be able to use that with a battery. :confused:

Sinusoid are sine waves. You would need an inverter to go from the DC of the battery to AC but most inverters do not produce a true sine wave. A regular house fan is mostly likely an AC motor; all mine are. You could maybe use a fan motor off your PC which is a DC motor.

The wheel chair motors are mostly likely DC so they could be usable.

Wikipedia has good info on AC and DC

EricH 03-04-2010 00:17

Re: Will a 1/3 horse power sump pump motor burn up at half power?
 
Let's put it this way: The motor runs on 115 volts. A 12V battery provides about a tenth of that.

So whatever the motor says it'll put out in terms of power, you can expect the actual power output to be no more than about a tenth of what it says if the voltage is the driving factor. (Current--amperage--is a different factor, and can have an effect as well.)

What you have is a household-voltage, low amperage motor. You won't trip a lot of breakers with it, but you won't be using its full potential.

Not ideal.

The exception would be if it has internal voltage regulators to take 115V down to 12V--and then I'd say to remove those for this use, as 12V is your max.

I'd go with the wheelchair motors instead--those are much more likely to be 12V or something in that range.

The fan motor would depend on what type of fan and the ratings on the voltage and amperage were.

Weird Al/ Tony 03-04-2010 00:19

Re: Will a 1/3 horse power sump pump motor burn up at half power?
 
alright thanks. ya see I'm trying to get a powerful motor that will be hard to stop while it is receiving power. that way it will be able to power my robot through all opposition. (this robot is for like a hobby, not the competitions) and I'm thinking that I have some older wheelchair motors, and other stuff. but they arent very fast and they dont have much power. I'd probably need either a gear box or some good belts to allow diffrent speed and torgue. I kinda think I know what i'm talking about. I mean I'm just getting on a team so I dont have alot of robotics experience. ::ouch::

kevin.li.rit 03-04-2010 00:22

Re: Will a 1/3 horse power sump pump motor burn up at half power?
 
Quote:

Originally Posted by Weid Al/ Toni (Post 947329)
alright thanks. ya see I'm trying to get a powerful motor that will be hard to stop while it is receiving power. that way it will be able to power my robot through all opposition. (this robot is for like a hobby, not the competitions) and I'm thinking that I have some older wheelchair motors, and other stuff. but they arent very fast and they dont have much power. I'd probably need either a gear box or some good belts to allow diffrent speed and torgue. I kinda think I know what i'm talking about. I mean I'm just getting on a team so I dont have alot of robotics experience. ::ouch::

Go FIRST Retro and use some 12 Volt Drill Motors. They'll come with gearboxes with high low speeds too! Judging by your team number your team might still have some.

EricH 03-04-2010 00:32

Re: Will a 1/3 horse power sump pump motor burn up at half power?
 
I think that you may want to talk to your local physics teacher. At the least, he can help you through some of the concepts and the math behind them.

I'll give a brief rundown of some of them.

Voltage: difference in electrical potential energy between two points.
Amperage or current: how fast that electrical energy can move.

Power (or energy): force*distance.
Work: power/time.
Torque: force * distance, usually referenced with regard to rotational motion. You'll want to know this eventually.

Gearboxes multiply and divide torque and rotational speed, which translates via wheels to linear power and linear speed.

BTW, you may want to look up some of John V-Neun's whitepapers. I think that those will help you with some of the math that is behind the design of a drivetrain, and quite possibly help you optimize the drive for the motors you have.

hipsterjr 03-04-2010 00:41

Re: Will a 1/3 horse power sump pump motor burn up at half power?
 
Please do not take this the wrong way, but coming from someone who has built homemade/ non-first robots, I can see that you may want to do a lot more studying on basic AC and DC electrical circuits and the wide variety of electrical motors before you get too deep into this project. At your level of experience, I would stay away from AC motors all together and stick with dc. AC is possible, but take a lot of know how to work on a battery powered robot. I took a digital circuits and industrial controls class that really helped me understand some of the questions mentioned here. I don't want to discourage you at all, just know what you are getting into before you spend too much time or money on something that won't work.
My $0.02

Weird Al/ Tony 03-04-2010 00:54

Re: Will a 1/3 horse power sump pump motor burn up at half power?
 
alright thanks guys. and I probably will stick to the DC stuff because I dont really have the money to work with converters and inverters and such. I'm probably going to be on here alot. and I'm also getting other info from other sites. I'm learning terms and what does what. i'm also studying basic electric diagrams. then there are the people who may be helping me from school so, i hope it will come together. and I'm pretty good with physics (without the classes), electrical is my main shortcoming. but yeah thanks. I will charish this time that i have spent on here forever! lol

Ether 03-04-2010 01:18

Re: Will a 1/3 horse power sump pump motor burn up at half power?
 
Quote:

Originally Posted by EricH (Post 947334)
Power (or energy): force*distance.

power and energy are not the same thing.

Quote:

Originally Posted by EricH (Post 947334)
Work: power/time.

you have that backwards.

power = work/time

Quote:

Originally Posted by EricH (Post 947334)
Gearboxes multiply and divide torque and rotational speed, which translates via wheels to linear power and linear speed.

torque translates to linear force, not linear power.


~

EricH 03-04-2010 01:40

Re: Will a 1/3 horse power sump pump motor burn up at half power?
 
Quote:

Originally Posted by Ether (Post 947344)
power and energy are not the same thing.

They aren't, but for some reason known to nobody, they share the same units. Joules in the SI, BTU and its equivalents in the Eng. system. (Eng. == either English or Engineering, which for functional purposes are indistinguishable.) This makes the calculations very similar when all's said and done.

150 kJ << without my telling you, is this power or energy?

150 kN-m << That's power, but to get that I had to expand the unit. Also note that that is a torque unit as well.

Energy has a number of ways to get to the kJ unit, none of them simple. Something about energy/mass * mass in a number of weird combinations makes it a little hard to translate out of handwriting.


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