HB25 Wire Gauge?
Hi everyone,
I'm currently redesigning my robot. I'm using the HB-25 motor controllers, transitioning them from powering a DC-550 Power Wheels motor to powering a Quickie P-190 wheelchair motor. I mention this, because I believe I'm going to be pulling more amps during normal operation. That being said, I was wondering what gauge wire I should use for both connection to the power system, and connection from the HB25 to the motors?
Thanks,
Luke
I'm currently redesigning my robot. I'm using the HB-25 motor controllers, transitioning them from powering a DC-550 Power Wheels motor to powering a Quickie P-190 wheelchair motor. I mention this, because I believe I'm going to be pulling more amps during normal operation. That being said, I was wondering what gauge wire I should use for both connection to the power system, and connection from the HB25 to the motors?
Thanks,
Luke
Comments
Good to see you here on Parallax's forum.
Have you checked the various Amp vs Gauge charts?
If you'll be pulling about 25A then it looks like you'll want 10 gauge wire. Apparently 12 gauge wire is enough for 20A.
The HB-25 is a pretty beefy motor controller but I don't know how much current those Quickie motor will pull. Do you know?
I haven't built large robots like you have but I'm wondering if you'll need an electric scooter motor controller for those motors. Do have a way to monitor the current?
Figure out from the mfr's spec sheet ( or measure with a meter) how many amps the motors draw (while under the load that you expect), and then you can determine wire size from charts like this.
Of course you know that we want to see pics of your robot too :thumb:
-MattG
Edit:Golly Dang Duane! So while I'm composing eloquence - you dash in and take the ribbon!
I've done that, and calculated 10 gauge wire. BUT, the screw terminals on the HB-25's are 4-40s, which seem a bit small to use for a ring terminal that will support 10 gauge wire. (I'm using this set)
So that's why I decided to pop on here and ask. I imagine I'm not the first person to use HB-25's on a wheelchair motor, so I'm curious on what others personally use for this application.
You can learn more about Artie the Robot by visiting his Facebook page - https://www.facebook.com/artie.the.robot
or his page at Lets Make Robots (which is more of a build log) - http://www.letsmakerobots.com/robot/project/rt-01
With the fuse protection, I don't mind hooking it up for HB-25s, and then if things go wrong and a fuse blows during normal operation, I'll upgrade to a Sabretooth 2x60. That is, unless Parallax has a higher current motor controller, as I'm obviously a fan of Parallax first. (BTW Parallax, you can thank Vern Graner for that one as my HB-25's were a donation from him)
I have a few HB-25's myself but I have yet to use them in a robot.
-MattG
Nice find, Duane! Now how about this dual display (v & a) 50A unit for $3.45? I'd double check that wire for high current.
http://www.ebay.com/itm/DC-4-5-30V-0-50A-Dual-LED-Digital-Volt-meter-Ammeter-Voltage-AMP-Power-ES9P-WS-/151414208575
Good to know that it operates in high humidity situations.
1 - HB-25 has a rating of 25 continuous amps.
2 - 25 amps appears to need 10 gauge wire on the lookup tables
3 - HB-25 has 4-40 screw mounts for terminals.
4 - Ring terminals for 10 gauge wire are too large to mount with 4-40 screws.
So, I have a few questions.
1 - Has anyone actually RAN the HB-25's on 25 continuous amps?
2 - What is the largest gauge wire anyone has hooked up to the HB-25's screw terminals?
3 - Did it need any special kind of connection?
4 - What is the largest continuous amp draw anyone here has done personally with an HB-25?
I'd really like to stick with the HB-25, but it seems to be the underdog of 25 amp motor controllers compared to the Sabertooth, which is why I'm asking on this forum first.
Thanks,
Luke
When I look at most of the charts, It appears that you need 10 gauge wire.
However, If you look at the chart Matt suggested (see Post #3), It appears that you only really need about 16gauge wire.
I'm thinking that the length of the wire run is of great concern.
On the Post#3 chart, there is a listing for Chassis wiring.
To me that means wire lengths of 2ft or less.
I'm for sure, no expert in this.
I do currently have a couple of HB-25's running on a platform I'm building.
You are demanding very much more current than my 5amp wiper motors draw, but Take another look at
the charts from Post#3.
Just my 2cents worth.
garyg
just so I have a point of reference, what gauge of wire are you using for your 5 amps on the HB-25?
Thanks.
I believe the term "Power Transmission Wire" is being mis-interpreted, but I could be wrong. Everything I've found so far called that is in regards to literally the overhead power lines from the utility company.
"Chassis wiring" is what we're talking about here - which means usually short distances. (As garyg has pointed out)
The amount of voltage drop and hence power dissipation in the wire is related to both its diameter and (as garyg points out also) the distance traveled - which determines the voltage drop over the length of run.
Therefore, I think (garyg) is right again: t appears that you only really need about 16 gauge wire. If you're running a longer distance I'd use 14 gauge if that's really what you're pulling.
And there's really only one sure way to find out, and that is to try it!
Therefore, If you want to give the HB-25's a shot - go for it. If they don't work for you we'll take 'em back and give you a refund.
That way we're not guessing, and you have no risk in being the "guinea pig" :thumb:
We know the guy that designed them
Try 'em if you like, and let us all know how it went (no fires or explosions please)
I mean heck, we say right on it's Product page "Features 25 A continuous current, 35 A surge @ 13.8 VDC"
-MattG
PS. Here's another chart and the top description seems to indicate that Power Transmission Wire is really, very conservatively rated vs. chassis wire https://www.hagemeyerna.com/getdoc/93f497f0-29a2-4a84-bd81-8e529103ced1/Wire--basics-of-Ampacity-or-Copper-Wire-Current-Ca.aspx
I'm using Autocraft part#AC460 Automotive Primary Wire.
I purchased it from one of the Automotive supply stores here in town.
It's 18gauge. My wire run is only approx. 12" from HB25 to the wiper motors.
The package says this should be good for 13Amps at 12Volts.
It seems to work for me.
Please do not miss the important info from Matt in Post#13.
It's important.
gg
A 1 foot section of 16AWG copper at 25 Amps will drop 0.208 Volts, round trip, which, I guess, means 2 feet of wire in total (going to the motor and coming back).
I think 12 awg should be fine as long as you keep the length of the wires under 3ft. I have a wheelchair that uses 12 awg wires from the motor controllers to the motors ( under 3ft), and 10 awg from the batteries to the motor controller. The original wire sizes when i first opened up the wheelchair are 10 awg to batteries, and 12awg to motors. I've ran the wheelchair under heavy load with no heating issues. I am using the Crossroad Talon SR motor controller rated at 60Amps continuous, but i think your HB25 should work fine.
Hoang
Do be careful to not the allow the power input terminals to touch the legs of the fuse. Not all #6 terminals have the same outer diameter. Bring your HB25 to the hardware store for visual check.
That's a sweet deal, Matt! Maybe it's time toi change your signature to:
"Ask me about the Lifetime Warranty on the Propeller BOE and HB-25s!"
I'll pick up some 14 gauge wire and some washers for the screw-posts to make sure the ring terminals don't slip through. I know it may seem like I'm over-thinking it, but I'd rather spend the time preparing and researching than the time/money replacing broken equipment and melted wiring. I'm a software guy, so I pretty much fumble my way around hardware/electronics by scouring the internets. I'll post some video of the results to youtube and share the link.