Fused disconnect required

[jumper]

Has repeatedly been mentioned the disconnecting means (the one required within 30 feet of the "trailer") must be suitable for use as service equipment - even if not installed as a "service disconnecting means".

How many items can you find that are "suitable for use as service equipment" that don't either contain overcurrent protective devices or at very least require additional overcurrent protection devices. When the device is a non fused safety switch - that would require additional overcurrent protection - most of those I have seen (especially if used on service conductors, though in this case are used on a feeder) require fuses as the protection. Can we disregard the fuse requirement here since this is a feeder as long as the available fault current doesn't present an issue with the switch rating? Many non fused safety switches are only rated 10kAIC unless protected with fuses. That said I bet the available fault current at OP's disconnect location is less then 10kA anyway.

You do not get the point.

OP kept wanting fuses in the beginning to protect feeder.....

Then was throwing in that 80 feet matters for the breaker to work....

Then at some point to protect interior panel, but since it is a trailer inside panel needs its own breaker....

The whole thread would have been different if we had started with 550.32(A), but we did not...

 

[kwired]

You do not get the point.

OP kept wanting fuses in the beginning to protect feeder.....

Then was throwing in that 80 feet matters for the breaker to work....

Then at some point to protect interior panel, but since it is a trailer inside panel needs its own breaker....

The whole thread would have been different if we had started with 550.32(A), but we did not...

I did get those points, pretty much right away. My reply is suggesting that overcurrent protection is typically required for a device to be suitable for use as service equipment. To go a little further that protection may be required to be fuses in certain conditions if the disconnecting means is a "safety switch".

Logically without getting caught up into too much code details, I agree it doesn't really make sense to require additional overcurrent protection at the disconnecting means in question here if the feeder breaker does protect the conductors all the way to the panel within the "trailer". But I also think that is what code wants when it states that disconnect must be suitable for use as service equipment. Such overcurrent protection is not limited to being fuses though, other then what may be listing requirements for a specific piece of equipment.

In fact if it were a regular building or structure and not a "trailer" I would even say the entire 80 feet run could apply feeder tap rules since it is outside, and could be only something like 6 AWG supplied by a 200 amp feeder breaker as long as it landed in a 60 amp breaker at the structure. I guess it still could be that way from the breaker to the disconnect in question, but thinking from that disconnect to the "trailer" probably can not be a tap conductor to comply with 550. But this is sort of off topic a little.

 

[jumper]

I did get those points, pretty much right away. My reply is suggesting that overcurrent protection is typically required for a device to be suitable for use as service equipment. To go a little further that protection may be required to be fuses in certain conditions if the disconnecting means is a "safety switch".

Logically without getting caught up into too much code details, I agree it doesn't really make sense to require additional overcurrent protection at the disconnecting means in question here if the feeder breaker does protect the conductors all the way to the panel within the "trailer". But I also think that is what code wants when it states that disconnect must be suitable for use as service equipment. Such overcurrent protection is not limited to being fuses though, other then what may be listing requirements for a specific piece of equipment.

In fact if it were a regular building or structure and not a "trailer" I would even say the entire 80 feet run could apply feeder tap rules since it is outside, and could be only something like 6 AWG supplied by a 200 amp feeder breaker as long as it landed in a 60 amp breaker at the structure. I guess it still could be that way from the breaker to the disconnect in question, but thinking from that disconnect to the "trailer" probably can not be a tap conductor to comply with 550. But this is sort of off topic a little.

Yes, all valid points because we all know this stuff.

OP has to learn how to walk before he can run. I could have easily told him that in the end he would wind up with a fused disco but I wanted to go through and discuss each point he brought up and work through it.

Think of like this: How many actual code sections are involved when installing SABCs to a resi kitchen countertop?

 

[codequestion]

Yes, all valid points because we all know this stuff.

OP has to learn how to walk before he can run. I could have easily told him that in the end he would wind up with a fused disco but I wanted to go through and discuss each point he brought up and work through it.

Think of like this: How many actual code sections are involved when installing SABCs to a resi kitchen countertop?

You said service disconnect does not mean fused. Now you are saying service disconnect means fused.

In the end i am still confused without straight answer.

This blog is cluttured because you wanted it clutter and then twist your answers even if i provided correct answer.

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[codequestion]

I did get those points, pretty much right away. My reply is suggesting that overcurrent protection is typically required for a device to be suitable for use as service equipment. To go a little further that protection may be required to be fuses in certain conditions if the disconnecting means is a "safety switch".

Logically without getting caught up into too much code details, I agree it doesn't really make sense to require additional overcurrent protection at the disconnecting means in question here if the feeder breaker does protect the conductors all the way to the panel within the "trailer". But I also think that is what code wants when it states that disconnect must be suitable for use as service equipment. Such overcurrent protection is not limited to being fuses though, other then what may be listing requirements for a specific piece of equipment.

In fact if it were a regular building or structure and not a "trailer" I would even say the entire 80 feet run could apply feeder tap rules since it is outside, and could be only something like 6 AWG supplied by a 200 amp feeder breaker as long as it landed in a 60 amp breaker at the structure. I guess it still could be that way from the breaker to the disconnect in question, but thinking from that disconnect to the "trailer" probably can not be a tap conductor to comply with 550. But this is sort of off topic a little.

Where it says suitable as service rated disconnect has to be fused in code?

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[jumper]

You said service disconnect does not mean fused. Now you are saying service disconnect means fused.

In the end i am still confused without straight answer.

This blog is cluttured because you wanted it clutter and then twist your answers even if i provided correct answer.

Sent from my SM-G935U using Tapatalk

Fine, if you want to use a safety switch, simplest way, it needs to fused in this application.

There is your answer. Good luck.

This is not a blog.

Where it says suitable as service rated disconnect has to be fused in code?

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It doesn’t.

 

[codequestion]

Fine, if you want to use a safety switch, simplest way, it needs to fused in this application.

There is your answer. Good luck.



It doesn’t.

Screw it engineer spec it as non fused and it his design. If its gonna req fused inspector would catch that if not i dont know.

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[jumper]

Screw it engineer spec it as non fused and it his design. If its gonna req fused inspector would catch that if not i dont know.

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As a David said, engineer may not have read 550.32. Ask he/she to verify.

Service disconnecting means can be all in one package or can be an assembly of parts.

Just putting fuses in any disconnect does not work either.

I made you go through those paces because you kept giving wrong reasons to want to do something.

Even when you got an answer right, it was for the wrong reason. That is no better than guessing.

 

[kwired]

Where it says suitable as service rated disconnect has to be fused in code?

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It doesn't. But the reality I tried to point out to you is that you will have a difficult time finding anything rated suitable for use as service equipment (which is a requirement for the disconnect you are questioning) that doesn't also have overcurrent protection integrated into it somehow, or requirements to supplement it with overcurrent protection somehow.

Simple non fused safety switches typically are not rated as stand alone service disconnecting means. You also keep mentioning fuses, circuit breakers are an option. Though I did earlier mention it is common that non fused safety switches may require fuses as the overcurrent protection in some instances, often is related to available fault current.

 

[jumper]

It doesn't. But the reality I tried to point out to you is that you will have a difficult time finding anything rated suitable for use as service equipment (which is a requirement for the disconnect you are questioning) that doesn't also have overcurrent protection integrated into it somehow, or requirements to supplement it with overcurrent protection somehow.

Simple non fused safety switches typically are not rated as stand alone service disconnecting means. You also keep mentioning fuses, circuit breakers are an option. Though I did earlier mention it is common that non fused safety switches may require fuses as the overcurrent protection in some instances, often is related to available fault current.

:thumbsup::thumbsup::thumbsup:

 

[jumper]

CQ, as I said I ran you through the NEC because I was trying to teach you some of the things one needs to look at and understand when using the NEC.

You are not installing an exterior disconnecting means with integral OCP because:

Distance.
OCP for the feeder.
550.11, applies to interior panel. That panels needs separate OCPD.
Article 225. 225 is a player here for the feeder, along with 550.33, but the disconnecting means sometimes required by 225 is not a factor since 550 requires one within 30’ of all trailers.
It seems like a good idea when you do not know what to do and are guessing.

Or 550.32 either in regards for a service disconnecting means, because your service disconnecting means is the really the breaker back at the panel.* This is a remote disconnect allowed by 550.32.

Now, 550.32 also requires that it be SUSE rated. Fuses by themselves do not accomplish this

kwired explains this well above. We touched on it earlier and 230.66.

If this were the service disconnecting means, integral OCP protection or an adjacent OCP device would be required. This is what the usual case is. This is what David was conveying.

550.32 just requires a SUSE rating disconnecting means and easiest way to do that is with a fused disco or breaker. Cost, efficiency, and ease of install. The OCPD is actually superfluous.

David gave you the best idea and is common. A small MB panel. A panel would be my choice also Add stuff if needed, ie receptacle, outside pole light, whatever.

Many of us have did these installs or designed /inspected them and know these variables. We learned this stuff, because we went through it. I was trying to get you to see all these points.

You are basically flying blind when you guess at things.

Do you understand now why I did what I did?

 

[jap]

Many of us have did these installs or designed /inspected them and know these variables. We learned this stuff, because we went through it. I was trying to get you to see all these points.

You are basically flying blind when you guess at things

That's where the difference is Jumper.
We learned from the school of hard knocks.

Not everyone has.

He's flying blind and guessing at things simply because he doesn't know.

For someone who doesn't know, I'd have to commend him for coming back with the responses he did.

To me this run took an odd turn at post #76.

Honestly, after reading everything that was posted, It's almost too much prompting, and , being drug out for 90 some post's, I'd probably get frustrated and say screw it too.


JAP>

 

[ggunn]

Fine, if you want to use a safety switch, simplest way, it needs to fused in this application.

I have held off asking this for the process to run its course. The NEC aside for a moment, why would a feeder which is fed by a breaker need OCPD at the other end? What could happen to the feeder that wouldn't open the breaker feeding it which would be ameliorated by OCPD at the other end?

 

[david]

I have held off asking this for the process to run its course. The NEC aside for a moment, why would a feeder which is fed by a breaker need OCPD at the other end? What could happen to the feeder that wouldn't open the breaker feeding it which would be ameliorated by OCPD at the other end?

Just off the top of my head you said setting the NEC aside, think of the elderly living in a mobile home having to go further than 30 feet to try and reset the breaker or change a fuse, especially in winter when they need there heat and a lot of rural areas water

The service main may trip but i would hope the over current with in 30 ft would trip first

 

[jap]

Just off the top of my head you said setting the NEC aside, think of the elderly living in a mobile home having to go further than 30 feet to try and reset the breaker or change a fuse, especially in winter when they need there heat and a lot of rural areas water

The service main may trip but i would hope the over current with in 30 ft would trip first

I really doubt this is the reason for the 30' rule.

Jap>

 

[jumper]

I have held off asking this for the process to run its course. The NEC aside for a moment, why would a feeder which is fed by a breaker need OCPD at the other end? What could happen to the feeder that wouldn't open the breaker feeding it which would be ameliorated by OCPD at the other end?

The OCPD at the outside disco does nothing in this situation.

Why the remote disco has to be SUSE rated is silly.

The requirement for the disco makes sense, but the SUSE rating is not needed.

225.36 for disconnecting means for outside feeders to another building used to have the similar requirements. Now you only need a SUSE rated disco for existing feeders that have no EGC.

550.32 needs to fixed.

 

[jumper]

Just off the top of my head you said setting the NEC aside, think of the elderly living in a mobile home having to go further than 30 feet to try and reset the breaker or change a fuse, especially in winter when they need there heat and a lot of rural areas water

The service main may trip but i would hope the over current with in 30 ft would trip first

But the panel inside has a main OCPD, 550.11(A), OCPD at the outside disco is silly.

 

[jumper]

That's where the difference is Jumper.
We learned from the school of hard knocks.

Not everyone has.

He's flying blind and guessing at things simply because he doesn't know.

For someone who doesn't know, I'd have to commend him for coming back with the responses he did.

To me this run took an odd turn at post #76.

Honestly, after reading everything that was posted, It's almost too much prompting, and , being drug out for 90 some post's, I'd probably get frustrated and say screw it too.


JAP>

When I started in this business it was in June, my first code class was in September of the same year.

Whether you take classes, learn it from the job, or both does not matter. But learn it you will if you are going to do this for a living.

Frustration can be overcome with knowledge. I was teaching a lesson. No one gets a free ride.

I come here to learn and participate. I am willing to try and help anyone if I can but I expect a little effort to.

This is the place to make mistakes and get help, but to make a mistake one must first make an attempt. I get answers wrong here all the time and get corrected, but I can show why I came up with the answer.

 

[david]

I really doubt this is the reason for the 30' rule.

Jap>

well he did say setting the NEC aside,i know he was referring to protecting the feeder and equipment

 

[david]

But the panel inside has a main OCPD, 550.11(A), OCPD at the outside disco is silly.

I know it does but the closes disconnect to the trailer that sees the total load is the outside disconnect.
out side AC units ,water pumps, out door sheds. all the site stuff.

i know it is off subject, but i cant tell you how many times the outside fuse blows before the main in the home

also in mobile home parks the service usually/ sometimes/ maybe is park equipment and the local disconnect is usually the tenants responsibility

a lot of park managers lock the service disconnect with a pad lock that the tenant does not have access to and must make a phone call to the manager if that trips.

the local disconnect is lockable and is left up to the tenant to lock or not to lock