| Author |
Message |
Malky
Unregistered guest
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| Posted on Tuesday, January 2, 2007 - 8:51 pm: |
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Can anyone tell me what the rating for the following is.
20mm Glass fuse, colour coded, wide blue band, narrow brown band, narrow brown band, narrow orange band.
Thanks in anticipation.
Regards
Malky |
Admin (Admin)
Board Administrator
Username: Admin
Post Number: 368
Registered: 10-2004
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| Posted on Thursday, January 4, 2007 - 4:42 pm: |
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Hello Malky,
This is something we do not stock and not something we have come across before. If it was a Picofuse then it would most likely be a 310mA but this is not a standard value for glass 20mm, the nearest being 315mA. Sorry we cannot help but maybe someone else knows on this forum. |
Geoff Cooper
Unregistered guest
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| Posted on Wednesday, May 9, 2007 - 5:56 pm: |
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What are the dimensions for the 1310-002 & -003 fuse holders please |
Admin (Admin)
Board Administrator
Username: Admin
Post Number: 484
Registered: 10-2004
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| Posted on Saturday, May 12, 2007 - 10:23 am: |
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Geoff,
The max dimensions with the covers on are:
1310-002 66 x 27 x 59 high
1310-003 86 x 27 x 59 high |
Eddie
Unregistered guest
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| Posted on Thursday, May 10, 2007 - 10:13 am: |
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Hi,
What's the maximum current on the 6 Way Standard Blade Holder (1310-003).
Thanks
Eddie. |
Admin (Admin)
Board Administrator
Username: Admin
Post Number: 485
Registered: 10-2004
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| Posted on Saturday, May 12, 2007 - 10:37 am: |
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Eddie,
We have checked the manufacturers literature and cannot find a figure. Whilst each way can take a maximum of a 40A fuse, there may well be a limit to the total current for the 4 or 6-way block. By this I mean that a 4-way block for example may not be able to take 160A due to the combined heating effect. What current are you after? |
Mark Mellors (Mark_m)
Member
Username: Mark_m
Post Number: 1
Registered: 1-2008
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| Posted on Tuesday, January 22, 2008 - 2:54 pm: |
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Hi,
I'm building a featherweight combat robot (13.6kg) with 4 x 9.6v drills running at 12V through 2 x 30amp electronize with external relays. Battery will be a 12V botpack, possibly increased to 15.6V or 24V depending on how the motors hold up.
For testing I'm going to use resetable circuit breakers to try to determine more accurately the current demands before choosing what fuses to use in combat.
What size fuse(s) would you suggest I start with? Can you suggest what correlation there will be between circuit breakers and maxi fuses? For example, if I find I'm happy with a 30amp circuit breaker protecting the speed controllers, what maxi fuse should I use in combat?
Images of the robot and my proposed wiring diagram are on this page: http://www.robowars.org/forum/viewtopic.php?t=1195
Thanks
Mark |
Admin (Admin)
Board Administrator
Username: Admin
Post Number: 680
Registered: 10-2004
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| Posted on Tuesday, January 22, 2008 - 7:57 pm: |
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Mark,
A 9.6V motor on 24V - good luck, hopefully they will last long enough to turn off again!
Firstly you have not given any indication of the motor power or current rating so we cannot give an exact answer. Fuses blow on the basis of time and current function, fuses will blow more quickly if its rating is greatly exceeded. You can compare circuit breakers with fuses but to do so you would need the time versus current curves for each and unfortunately this is something we do not have. As a rule of thumb, we use a fuse rated to the full load current of the motor. Fuses will take a long time to blow at their nominal rating but exceed this by a factor of two or more and they will blow quite quickly - hopefully quick enough to prevent a motor from burning out if stalled.
This is not a precise science with robots and you are better off starting lower and then increasing in value. Our Zeobot robot ran with two motors per side drawing about 6A at the rated load but would infrequently blow a 15A fuse but not a 20A fuse on the Electronize controller.
What are you looking for the fuse to protect - the motor or speed controller? It is not uncommon to use a fuse in the supply to a speed controller and use the current limiting function (if provided) of the controller to protect the motor. The Electronize controllers do not provide a current limiting function other than by the fuse.
Motors in combat robots can draw very high currents when the motor is reversed which can be as high as the stall current. Most roboteers do not use fuses as they would sooner pop a speed controller (then try and return it under warranty) rather than have a fuse blow and lose a fight but we have always used them and always will.
In summary, decide what the fuse is there to protect, from there estimate the maximum current duration and use that as a starting value. Fuses are better than circuit breakers in combat robots but using a circuit breaker to size an automotive fuse is unlikely to be successful due to their different time / current characteristics. |
Mark Mellors (Mark_m)
Member
Username: Mark_m
Post Number: 2
Registered: 1-2008
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| Posted on Wednesday, January 23, 2008 - 1:34 pm: |
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Thanks for the quick response. I've realised I could have done some of the research myself and have managed to find a couple, of data sheets showing the time/current charts for both maxi fuses and circuit breakers:
www.mta.it/documents/caa8290ae7700e4f34c7e25752740472
www.k0bg.com/images/pdf/maxifusedata.pdf
http://www.rapidonline.com/netalogue/specs/26-7730e.pdf
So hopefully I will have somewhere to start when changing out the circuit breakers.
WRT 9.6V drills on 24V, my last robot was a 5kg one driven by two 9.6V drills at 24V. It was extremely fast but kept fusing the relays on the electronizes. I only burnt one motor out in a couple of hours of testing (not combat) and that was because of a melted endbell. If I go to 24V in future I will probably also change the motors for higher voltage ones as I don't want to take the risk again.
I suppose there are two ways to size the fuse, what is the maximum expected load and what can the components withstand. I don't know what the stall current or torque constant of the motors is, so we can't work from that direction without me taking more measurements. I was mainly looking for fuses to protect the batteries and speed controllers, as they are the expensive bits. What fuse would you recommend for a 30A electronize?
Why would you say fuses are better than circuit breakers in combat robots? Just because of weight and size or do they perform better in some way?
Thanks again for the help.
Mark |
Admin (Admin)
Board Administrator
Username: Admin
Post Number: 682
Registered: 10-2004
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| Posted on Thursday, January 24, 2008 - 7:17 pm: |
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Hi Mark,
Good links there. Protecting the batteries is a good idea especially for certain technologies. Protecting a speedo is not so easy as can be a race against time as the semiconductors can pop very quickly. For example, a motor winding short can pop the MOSFET's in uS rather than seconds. Fuses and circuit breakers provide for a thermal protection rather than electronic. As the Electronize does not have electronic current limit, the fuse is there to protect the speedo primarily from thermal overload which is still a good idea.
You ideally want a fuse sized to protect the controller and battery. A 30A controller with a 30A fuse or circuit breaker will not blow with a 30A current draw. Draw 60A and the breaker will still take 3-4 seconds, a Maxi fuses make blow in under 1 second. As you can see, testing on a breaker than a fuse could give quite different results. You will be drawing most current when accelerating or push or stalling. You will want to be able to cope with the accelerating currents as longs as it remains within the speedo rating but have the fuse pop if the pushing or stall currents exceeds the current rating. I would still keep the 30A fuse for the Electronize and if you find it pops but the controller reamins cool, review it then.
Why do i prefer fuses, because they can better handle short term peak current surges without damage unlike the thermal circuit breakers. Also, I have always been concerned on relying on a sprung loaded contact that could open during heavy shocks as commonly found in combat.
Happy to help.
Regards
Paul |
RAFIK LUNAT
Unregistered guest
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| Posted on Sunday, October 5, 2008 - 12:18 pm: |
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I HAVE A BLOWN FUSE IN MY VALLIANT BOILER AND CANT SEEM TO GET HOLD OF A SPARE. IT IS A 20MM GLASS FUSE AND IT IS MARKED AS T2E250V. I HAVE SEARCHED EVERYWHERE AND CANT SEEM TO GET A REPLACEMENT. I WOULD GREATLY APPRECIATE IT IF YOU COULD HELP ME. THANX IN ADVANCE. |
Admin (Admin)
Board Administrator
Username: Admin
Post Number: 896
Registered: 10-2004
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| Posted on Tuesday, October 7, 2008 - 7:31 pm: |
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Hi,
That is not a code we recognise. It is not uncommon to find spare fuses near to or on the boiler PCB or its cover - worth checking. The fact that the fuse has blown could well suggest that there is a genuine fault on the PCB / pump. It sounds like the mains 2A fuse which means the pump or possibly the fan. We are not experts on boilers by the way, just offering an educated guess. |
donblanc1
Unregistered guest
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| Posted on Monday, January 19, 2009 - 2:35 pm: |
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Std blade fuse holder bottom entry. Part No. 1310-006. Is there a clear cover available for this item?? Thanks |
Admin (Admin)
Board Administrator
Username: Admin
Post Number: 956
Registered: 10-2004
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| Posted on Monday, January 19, 2009 - 6:57 pm: |
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Sorry no there isn't. We do stock 4 and 6 way fuse holders that do come with a clear cover in case that is of interest. |
clodhopper
Unregistered guest
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| Posted on Saturday, January 30, 2010 - 1:35 pm: |
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What is the cable size for your maxi blade fuse holder 1310-004 and its current rating? Thanks |
Admin (Admin)
Board Administrator
Username: Admin
Post Number: 1198
Registered: 10-2004
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| Posted on Wednesday, February 10, 2010 - 4:47 pm: |
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Thank you for pointing this out, the website has been updated to include "cable size is 8 AWG rated at 80A". |
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