Chief Delphi

Chief Delphi (http://www.chiefdelphi.com/forums/index.php)
-   Electrical (http://www.chiefdelphi.com/forums/forumdisplay.php?f=53)
-   -   Victor connect to 30 A instead of 40 A (http://www.chiefdelphi.com/forums/showthread.php?t=126065)

Rafa12 08-02-2014 14:53

Victor connect to 30 A instead of 40 A
 
We connected our visitor to a 30 A to our distribution board, does it cause víctor any damage or to the robot? :confused:

eddie12390 08-02-2014 14:59

Re: Victor connect to 30 A instead of 40 A
 
The only difference between plugging it into a 30A port vs a 40A port is that the breaker could potentially trip earlier. It won't be harmful.

Rafa12 08-02-2014 15:02

Thanks it helped a lot :D

Al Skierkiewicz 08-02-2014 23:31

Re: Victor connect to 30 A instead of 40 A
 
There is no rule about breaker size and the controller. You could use a 20 amp breaker with a Victor as long as the wire size from the PD is #18 AWG minimum.

yash101 09-02-2014 01:04

Re: Victor connect to 30 A instead of 40 A
 
When talking big power like this, less is better :D
30 Amps means that less current (hoh flowing through the pipe) is flowing than the 40 amps, or greater current.

That means that:
A) Motor Controllers Cooler
B) Fuses trip easier
C) You can use thinner wires
D) You fuse is smaller
E) You will ask yourself why a motor suddenly shuts down at ~75% power!

ksafin 09-02-2014 01:57

Re: Victor connect to 30 A instead of 40 A
 
Quote:

Originally Posted by yash101 (Post 1339964)
When talking big power like this, less is better :D
30 Amps means that less current (hoh flowing through the pipe) is flowing than the 40 amps, or greater current.

That means that:
A) Motor Controllers Cooler
B) Fuses trip easier
C) You can use thinner wires
D) You fuse is smaller
E) You will ask yourself why a motor suddenly shuts down at ~75% power!

I think "less is better" isn't accurate.

Using a 30 amp fuse does not mean "less current" flowing. It just means that once the current draw reaches 30 amps, it'll pop, instead of at 40. That is to say, fuse doesn't determine current.. a victor in identical conditions will draw X current in both the 30 amp and 40 amp fuse, but will not draw > 30 amps in the 30 amp fuse.

Motor controllers cooler - not really. Again, this is dependent on the stress involved. They'll only be cooler by the consequence of stopping due to a fuse pop.

Fuse trips easier - no bueno.

Thinner wires - more resistance, meaning hotter wires. For most motor applications you can end up pulling quite a bit of current which in extreme cases could even melt your wires.

seg9585 09-02-2014 03:32

Re: Victor connect to 30 A instead of 40 A
 
When choosing breaker (and subsequent wire size), I typically consider 2 factors:
- Motor selection
- Duration of usage in match

I use 40amp on CIMs almost exclusively due to their power draw. For smaller motors like PG71/188, usually or 30 amp unless its a continuous-usage motor (for example some conveyors) because of the heat produced in the wiring. Window motors usually 20 amp, Mini CIM either 30 or 40, Van Door/Snow Blower 30 amp.

Moral of the story, determine the power draw based on your motors, not speed controllers. I recommend checking the stall current draw for each motor (those specs are widely available) and judge accordingly.

Daniel_LaFleur 09-02-2014 08:55

Re: Victor connect to 30 A instead of 40 A
 
Quote:

Originally Posted by seg9585 (Post 1339998)
When choosing breaker (and subsequent wire size), I typically consider 2 factors:
- Motor selection
- Duration of usage in match

I use 40amp on CIMs almost exclusively due to their power draw. For smaller motors like PG71/188, usually or 30 amp unless its a continuous-usage motor (for example some conveyors) because of the heat produced in the wiring. Window motors usually 20 amp, Mini CIM either 30 or 40, Van Door/Snow Blower 30 amp.

Moral of the story, determine the power draw based on your motors, not speed controllers. I recommend checking the stall current draw for each motor (those specs are widely available) and judge accordingly.

This is not quite right.

When choosing a breaker, choose it by the wire gauge attached to that breaker as breakers and fuses only protect the wiring.

Now to go further, you choose your wire gauge and drive circuit(victor, talon, spike, etc.) by the load (motor, solenoid, etc.) on the wire.

IndySam 09-02-2014 09:02

Re: Victor connect to 30 A instead of 40 A
 
Wire size is not a problem. The wire size is a minimum not maximum. You can use the same size wire on a 30a as you can on a 40a.

Daniel_LaFleur 09-02-2014 09:11

Re: Victor connect to 30 A instead of 40 A
 
Quote:

Originally Posted by IndySam (Post 1340014)
Wire size is not a problem. The wire size is a minimum not maximum. You can use the same size wire on a 30a as you can on a 40a.

Only as long as the wire gauge is good for 40A

FrankJ 09-02-2014 10:58

Re: Victor connect to 30 A instead of 40 A
 
The idea that the breaker is sized just to protect the wire is facilities logic. When you size breakers or other over current devices on a piece of equipment, like a robot, you size them for the protection of the load. You size the wire to suit.

A smaller breaker won't hurt your victor, it might save your motor.

Daniel_LaFleur 09-02-2014 12:13

Re: Victor connect to 30 A instead of 40 A
 
Quote:

Originally Posted by FrankJ (Post 1340037)
The idea that the breaker is sized just to protect the wire is facilities logic. When you size breakers or other over current devices on a piece of equipment, like a robot, you size them for the protection of the load. You size the wire to suit.

A smaller breaker won't hurt your victor, it might save your motor.

Sorry, FrankJ, but I respectfully disagree.

A breaker or fuse is no where near fast enough to protect a load from overcurrent (look at the trip specs).It is, instead, there to protect the rest of the wiring from an overcurrent event once a electrical failure has occurred. Thus, you size the wire to suit the load and you size the fuse/breaker to protect the wiring.

IndySam 09-02-2014 12:20

Re: Victor connect to 30 A instead of 40 A
 
Quote:

Originally Posted by Daniel_LaFleur (Post 1340059)
Sorry, FrankJ, but I respectfully disagree.

A breaker or fuse is no where near fast enough to protect a load from overcurrent (look at the trip specs).It is, instead, there to protect the rest of the wiring from an overcurrent event once a electrical failure has occurred. Thus, you size the wire to suit the load and you size the fuse/breaker to protect the wiring.

Daniel, a breaker is there to protect load and the wiring. If you use 12ga wire instead of 14ga with a 30a breaker you are actually adding a level of security. The wire will be much less likely to be damaged if you have a load that trips the breaker.

FrankJ 09-02-2014 13:31

Re: Victor connect to 30 A instead of 40 A
 
Admittedly the snap action breakers we use don't have the best protection. The right fuse will clear in half a wave length. The right circuit breaker is right behind that.

Most of the legal motors have out grown the Spike since a momentary stall or loaded start will blow the fuse the spike. So that leaves the talons, victors, & jags that will happily burn out the smaller motors. Sizing the breaker closer to the running load of the motor will give some protection since that is the legal option.

In other applications... You use molded case breakers or fuses for dead short protection for motor/controllers in conjunction with overload devices that are not fast enough for a short. The rectifiers in my plant use fast acting fuses to protect solid state components. I use fuses on my plant IO so one short doesn't take down the entire control system. A typical industrial power supply will current limit & chug happily along at a dead short so wire protection is not an issue.

Alan Anderson 09-02-2014 21:09

Re: Victor connect to 30 A instead of 40 A
 
Quote:

Originally Posted by FrankJ (Post 1340092)
A typical industrial power supply will current limit & chug happily along at a dead short so wire protection is not an issue.

A robot battery, on the other hand, will happily dump hundreds of amps into a short. Protecting against wires catching on fire is definitely an issue.

There are only two things that can reasonably cause a robot circuit breaker to trip. One is a short in the wiring -- perhaps a connector has come loose and randomly touches something it shouldn't, or a mechanism has damaged the insulation. The breaker must be sized to keep the current from exceeding what the wires are safely capable of carrying. The other is a fault in whatever the wires are connected to -- either an electrical component has failed and is pulling much more current than it's designed to, or a motor is stalled because of a mechanical (or design) failure. In almost every case, the damage is what causes the overcurrent condition in the first place, so even a fast-acting fuse won't prevent it.


All times are GMT -5. The time now is 19:23.

Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi