# Kelly 14500B and Curtis 1231C-8601



## fugdabug (Jul 14, 2008)

I had mentioned in another thread the size of the Curtis controller I received in the UPS drop the other day from KTA services in California. Looking at the sizes of the two controllers alone tells some tales:
1. to handle 500A and up to 168VDC requires the ability to house the components guaranteed to provide the current control.
2. the surface area of the controller must allow for heat dissipation adequate to keep the controller from cutting out due to over heating in normal usage.
3. Simplicity is the key to a controller.
4. cost: Kelly 14500B @ $US1400.00, Curtis $US1495.00 (neither cost includes the shipping). So though I got the 14500B due to an accounting error on the original purchase (I was sent a 14500A listed as a 14500B) in my warranty replacement,.. the cost is comparable, depending on the price you get from a number of suppliers.
5. Curtis does not 'bargain you' into a different replacement or upgrade, Kelly does try... and they DO NOT REFUND MONEY.
6. Curtis is a well established company with good ratings, and for a SIMPLE, easy to use controller that is well-backed by its company. Kelly has not proven itself that established in technology or warranty or quality.

Bottom line, you get what you pay for... 

IF Otmar would ever sell his business to someone who would get it up and running and producing to meet the present need we would probably see a real progressive rebuild of technologies in this country. And if the other companies that are out there would use TRUE QUALITY PARTS and Quality Assurance, we might see a reasonably prices heavy duty line of controllers available in a spectrum of price ranges and usability options.

Let us hope this happens and SOON...

Respectfully submitted,
Fugdabug


----------



## CPLTECH (Sep 14, 2007)

Quality and reliability is sure worth the few extra bucks.

Thanks for the comparison pix. As a side note, I hope you intend to put a nice heat sink, heat sink grease, and a fan on that Curtis. My unit is mounted upside down to accommodate the extra aluminum fins as the mosfets are mounted on the thick part (formerly the bottom).

94S10 1231C-8601


----------



## fugdabug (Jul 14, 2008)

CPLTECH said:


> Quality and reliability is sure worth the few extra bucks.
> 
> Thanks for the comparison pix. As a side note, I hope you intend to put a nice heat sink, heat sink grease, and a fan on that Curtis. My unit is mounted upside down to accommodate the extra aluminum fins as the mosfets are mounted on the thick part (formerly the bottom).
> 
> 94S10 1231C-8601


Oh yeassss! I have been contemplating whether I should purchase the set of fins I found posted in a thread for US$45 OR my other option is to build a nice set of COPPER fins. I have a lot of 14ga. copper sheet at my disposal right now and I have been designing a set of heatsink fins. I just recently purchased the 2nd Edition of "Build Your Own Electric Vehicle".. which is updated as of about 2007. Was greatly impressed with the need for COOLING on the controller... which is a 'beast'! My Stars that thing is humungus... So my leaning is toward the Copper heatsink with a two fan (in and out) blow-through unit. I also have been scrounging 4" 12V fans from some servers that were scrapped out. I intend to make sure heat dissipation is increased exponentially on this controller! 

8287-706149 1231C-8601


----------



## GEARS-N-GREASE (Apr 7, 2008)

fugdabug said:


> ... which is a 'beast'! My Stars that thing is humungus... So my leaning is toward the Copper heatsink with a two fan (in and out) blow-through unit. I also have been scrounging 4" 12V fans from some servers that were scrapped out. I intend to make sure heat dissipation is increased exponentially on this controller!
> 
> 8287-706149 1231C-8601


Copper is a great conductor, but it's properties make it hold (and longer to achieve)heat more then alternatives like aluminum. If you are seeking to cool , aluminum would probably be you best bet for this


----------



## major (Apr 4, 2008)

GEARS-N-GREASE said:


> Copper is a great conductor, but it's properties make it hold (and longer to achieve)heat more then alternatives like aluminum. If you are seeking to cool , aluminum would probably be you best bet for this


Hey G-N-G,

Look up thermal conductivity for Cu and Al. You might want to rethink your statement.

Regards,

major


----------



## GEARS-N-GREASE (Apr 7, 2008)

Ok. I will rephrase, copper is probably better to collect the heat due to it's thermal conductivity, but aluminum is better to disappate the heat.

here is an online experiment concerning this http://www.benchtest.com/alum&copp.html


----------



## major (Apr 4, 2008)

GEARS-N-GREASE said:


> Ok. I will rephrase, copper is probably better to collect the heat due to it's thermal conductivity, but aluminum is better to disappate the heat.
> 
> here is an online experiment concerning this http://www.benchtest.com/alum&copp.html


 
Interesting, G-N-G,

So the better material for the heat sink or cooling fins might actually depend on your thermal duty cycle. I thought just better conduction of the heat to the larger surface area was the trick.

Live and learn,

major


----------



## fugdabug (Jul 14, 2008)

GEARS-N-GREASE said:


> Copper is a great conductor, but it's properties make it hold (and longer to achieve)heat more then alternatives like aluminum. If you are seeking to cool , aluminum would probably be you best bet for this


Hmmmm... Well I do have aluminum to hand. And 1/4"x2" bar material would work welded to a plate as fins, so I might just do that. Right now expenses are a consideration... Being it is winter and we have been hit with a deflationary period, not too many customers looking for expensive gifts at this time. So... I may do a combination of copper plate with an aluminum heatsink applied to it. I use the same set-up on my CPU's...
AND I also noticed that most of the heatsink fins in power units are aluminum! (Knock knock! puddin' head!!!)... makes more sense to me!
Thanks


----------



## Guest (Dec 10, 2008)

You gotta have a good heat sink on any controller. My current controller I am using has a pretty thick base but it is not able to dissipate the heat fast enough. With out a sink it heated enough to go into safety mode and boy was it hot. With my current sink it went 15 miles at full out speed and in the end it was barely even warm. The big fat aluminum block I am using as a sink can pull that heat away to keep the controller very cool. I decided on trying the block to see if just plain mass can keep the controller cool. So far the answer is absolutely yes. This way I do not have to have a fan and I keep the extra energy user parts off my conversion. I am trying to keep it as simple but functional as possible. So far so good. The fan is good but if for any reason the fan fails and you don't know, it could still over heat with a thin base with fin heat sink. Not mine. 

Pete : )





fugdabug said:


> Hmmmm... Well I do have aluminum to hand. And 1/4"x2" bar material would work welded to a plate as fins, so I might just do that. Right now expenses are a consideration... Being it is winter and we have been hit with a deflationary period, not too many customers looking for expensive gifts at this time. So... I may do a combination of copper plate with an aluminum heatsink applied to it. I use the same set-up on my CPU's...
> AND I also noticed that most of the heatsink fins in power units are aluminum! (Knock knock! puddin' head!!!)... makes more sense to me!
> Thanks


----------



## fugdabug (Jul 14, 2008)

gottdi said:


> You gotta have a good heat sink on any controller. My current controller I am using has a pretty thick base but it is not able to dissipate the heat fast enough. With out a sink it heated enough to go into safety mode and boy was it hot. With my current sink it went 15 miles at full out speed and in the end it was barely even warm. The big fat aluminum block I am using as a sink can pull that heat away to keep the controller very cool. I decided on trying the block to see if just plain mass can keep the controller cool. So far the answer is absolutely yes. This way I do not have to have a fan and I keep the extra energy user parts off my conversion. I am trying to keep it as simple but functional as possible. So far so good. The fan is good but if for any reason the fan fails and you don't know, it could still over heat with a thin base with fin heat sink. Not mine.
> 
> Pete : )


Ah Si, Signore,.. Questiones??? WHERE did you get the controller, how much and is it still available to the public???... I have never heard of this company or seen such a controller around... did you in fact buy it direct?
Inquiring minds want to know... Also: what is its rating?


----------



## major (Apr 4, 2008)

GEARS-N-GREASE said:


> Ok. I will rephrase, copper is probably better to collect the heat due to it's thermal conductivity, but aluminum is better to disappate the heat.


This Cu vs Al heat sink thing jarred a memory. Some of the heat sink makers are starting to offer copper products. Here's one 

http://www.vettecorp.com/products_services/heat_sinks/ps_hs_air_cooled_copper.php# 

And a quote from that site "Vette utilizes copper in many of its high performance solutions due to its higher thermal conductivity compared to aluminum."

They also offer combos of Al and Cu. 

Regards,

major


----------

