Crimp Connectors Amperage

[TJim]

Hey!

I am doing a project using an old Jeep PDC to make an auxiliary fuse box. I am going to do my own wiring.

I would like to ask If anyone knows about amperages of the crimp connectors.

Is it safe to use those kind of connectors in 50-60A relays?

For example, for a device rated for 45A, I am going to use a 50A fuse + 50-60A relay + wire rated for at least 60A. Is it safe to use a crimp connector like the above for those kind of Amps?

 

[MutantNinjaTJ]

Use the correct size crimp connector for the size wire you are using and yes they are rated for the amp load. Use a connector sized for 12ga wire it will handle the 28 amps the wire is rated for. Beware that AC amps and DC amps are not the same. DC needs larger wire then AC does. Your 60amp load may need something around 8ga wire with insulation rated for DC amperage. The connectors pictured in your post are AC rated for 14/16 gage wire, maybe about 10/12 amps, You will need some big Blues for you application

 

[Imapepper]

Beware that AC amps and DC amps are not the same.

Untrue, fake news, alternate fact.

 

[TJim]

Thank!
Yeah, I know that I am not going to use the red one, I just wanted to show the style of the connector.

Another question is that I want to use a wire rated for 60A. If the compressor is for example 7 feet away from the PDC. Can I run a 10gauge wire from the fuse to the #30 of the relay and a 10gauge wire from the #87 of the relay to a connector (photo #1) attached to the side of the PDC, and finally to run from the connector to the air compressor a 8 gauge wire?

OR should I use the same gauge wire in both (3) connections? (1. Fuse to #30Relay, 2. #87Relay to Connector, 3. Connector to Device)

Photo #1:

 

[TurboTJ]

Use the correct size crimp connector for the size wire you are using and yes they are rated for the amp load. Use a connector sized for 12ga wire it will handle the 28 amps the wire is rated for. Beware that AC amps and DC amps are not the same. DC needs larger wire then AC does. Your 60amp load may need something around 8ga wire with insulation rated for DC amperage. The connectors pictured in your post are AC rated for 14/16 gage wire, maybe about 10/12 amps, You will need some big Blues for you application

Strictly speaking, for the same RMS current AC requires larger wire than DC. This is due to skin depth increasing the effective resistance of the conductor. Skin depth is the depth in the conductor where the AC current is reduced to 37% of that at the surface. For copper at 60 Hz it is about a third of an inch so it isn't going to make much of a difference in this instance. It is a big deal for high tension power lines which usually have a steel core for strength and an aluminum outer layer which carries the current. Making the entire cable out of aluminum would not decrease the effective resistance much because skin depth would prevent much of the current from flowing in the core.

Having said all of that, there may be some reason for cable being rated different for AC or DC but I have never heard of any other than of course for insulation characteristics such as breakdown voltage, temperature ratings, etc.

 

[PJOJeep]

The size of the wire is also dependent on it’s length. I’ve attached a chart for automotive wire, crimp connectors are usually found for 10 GA and smaller, after that you will likely need either the mechanical (screw type shown above), or battery connectors that require a special crimp tool.

You also mention some post references for a standard bosch automotive relay, those are usually rated at 30A, maybe up to 40A. Look for 60A solenoid. I have a 500A solenoid to isolate my winch, operates that same as the bosch relay, but at a higher current rating.

 

[pagrey]

Untrue, fake news, alternate fact.

Research power factor if you are interested. I guess you could be joking?

 

[Goatman]

Leaving the science stuff to others, I recommend using g the newer crimp connectors that also have heat shrink tubing instead of just that colored plastic end. They also have glue inside the heat shrink. So now all the stress of the connection is spread out the whole length of the connection plus helps to keep water out also. They are very cheap on Amazon and do a super job. A less than 100% perfect crimp will still hold and function for years.

 

[TurboTJ]

Leaving the science stuff to others, I recommend using g the newer crimp connectors that also have heat shrink tubing instead of just that colored plastic end. They also have glue inside the heat shrink. So now all the stress of the connection is spread out the whole length of the connection plus helps to keep water out also. They are very cheap on Amazon and do a super job. A less than 100% perfect crimp will still hold and function for years.

Ditto what Goatman said. That is all that I use now. They are so much better than ordinary crimp connectors that always leave you guessing whether you have a good connection or not.

 

[tworley]

I'd also recommend a good pair of crimpers. I bought a ratcheting crimp tool last year and it is above and beyond the cheesy crimp/strip tool that comes with most electrical sets.

 

[TJim]

The size of the wire is also dependent on it’s length. I’ve attached a chart for automotive wire, crimp connectors are usually found for 10 GA and smaller, after that you will likely need either the mechanical (screw type shown above), or battery connectors that require a special crimp tool.

You also mention some post references for a standard bosch automotive relay, those are usually rated at 30A, maybe up to 40A. Look for 60A solenoid. I have a 500A solenoid to isolate my winch, operates that same as the bosch relay, but at a higher current rating.

View attachment 151602

Do you think I should prefer a 60A solenoid connected from the battery to the air compressor, which will be triggered my a smaller relay in my Aux PDC? or just a 60A relay in my aux PDC?

 

[Imapepper]

Research power factor if you are interested. I guess you could be joking?

current equals voltage divided by resistance, period.

 

[pagrey]

current equals voltage divided by resistance, period.

Here it is in black and white, don't know what else to say. I've got a few books I can mail you or recommend. Why choose to stay blind to the world and how it really works, what's to gain?

https://en.wikipedia.org/wiki/Power_factor

 

[TurboTJ]

Here it is in black and white, don't know what else to say. I've got a few books I can mail you or recommend. Why choose to stay blind to the world and how it really works, what's to gain?

https://en.wikipedia.org/wiki/Power_factor

While it is true that power factor of less than one in an AC system will result in current higher than what would be required with a power factor of one, current is still current whether AC or DC. If you have 10A you need wire rated for 10A and if you have 100A your need wire rated for 100A, irrespective of what the power factor is. I think I can see your point though. If you have a highly inductive AC load that dissipates 100 Watts in a 120V system, the current will be higher than 100/120. Whatever that current is however will determine the size of the wire required.

 

[pagrey]

Whatever that current is however will determine the size of the wire required.

If a motor is rated at 100A and you select wire rated at 100A you can have problems, ignoring power factor the 100A motor can pull 120A over the wire. Sure, if you have overhead it wont matter but that doesn't mean "amps is amps." The whole point is that for AC power lines you can't simply use the rated current of a device to figure out the wire gauge and when somebody says AC current isn't like DC current that's what they are talking about. You can choose to ignore it but that doens't mean it doesn't exist.

 

[TurboTJ]

If a motor is rated at 100A and you select wire rated at 100A you can have problems, ignoring power factor the 100A motor can pull 120A over the wire. Sure, if you have overhead it wont matter but that doesn't mean "amps is amps." The whole point is that for AC power lines you can't simply use the rated current of a device to figure out the wire gauge and when somebody says AC current isn't like DC current that's what they are talking about. You can choose to ignore it but that doens't mean it doesn't exist.

I am not saying to ignore what the actual current is. The wire should be sized for the actual current, whether AC or DC.

 

[Brokeass Boater]

Hey!

I am doing a project using an old Jeep PDC to make an auxiliary fuse box. I am going to do my own wiring.

I would like to ask If anyone knows about amperages of the crimp connectors.
View attachment 151578

Is it safe to use those kind of connectors in 50-60A relays?

For example, for a device rated for 45A, I am going to use a 50A fuse + 50-60A relay + wire rated for at least 60A. Is it safe to use a crimp connector like the above for those kind of Amps?

Your example has your fuse at a higher amp rating then your device, that could kill what ever your device is before the fuse interrupts the power. I would not wire 60 amps to those connectors, not sure what your trying to build, but 50-60 amps is a decent load,,,gregg

 

[TJim]

Your example has your fuse at a higher amp rating then your device, that could kill what ever your device is before the fuse interrupts the power. I would not wire 60 amps to those connectors, not sure what your trying to build, but 50-60 amps is a decent load,,,gregg

It is an air compressor with maximum amperage draw 45A. It is recommended to use a slightly bigger fuse that the needs of the accessory (otherwise If I use a 45A fuse, the fuse will be blown by the normal operation of the device)

I am going to " build" an Auxiliary Relay & Fuse box, by using a Power Distribution Center (PDC) of another Jeep. (photo)