cable stackers
- Thread starter pfelmey
- Start date
- Status
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: cable stackers
I know nothing about the specific product or device you have named. But as an Engineer, I have done calculations that evaluate the impact of one cable on other nearby cables. As a result, I have formed some opinions. One is that simply maintaining a constant separation along the length of a run is not enough to prevent interaction between conductors (by that I mean that the heat from one causes the other to get hotter, and thereby to reduce its useful ampacity). Another is that the 7.5 inches that appear in, for example, Figure B.310.1, are not enough either.
Good Question!!! What I mean by that is that you have touched upon one of my favorite topics. My issue is, ?What constitutes ?enough space,? so that derating is no longer required??
I know nothing about the specific product or device you have named. But as an Engineer, I have done calculations that evaluate the impact of one cable on other nearby cables. As a result, I have formed some opinions. One is that simply maintaining a constant separation along the length of a run is not enough to prevent interaction between conductors (by that I mean that the heat from one causes the other to get hotter, and thereby to reduce its useful ampacity). Another is that the 7.5 inches that appear in, for example, Figure B.310.1, are not enough either.
george t. everett
Senior Member
- Location
- New York
Re: cable stackers
If all the wires were on the same circuit , why would you need to derate?
If all the wires were on the same circuit , why would you need to derate?
- Location
- Massachusetts
Re: cable stackers
The only thing that matters is if they are current carrying conductors.
There is no exception to the derating rules for conductors on the same circuit.
The only thing that matters is if they are current carrying conductors.
A
a.wayne3@verizon.net
Guest
Re: cable stackers
Yes Bob they are but they are not bundled...I agree the free air space between them negates bundling,but if you but 2 wires in the larger space then derating occurs.
Yes Bob they are but they are not bundled...I agree the free air space between them negates bundling,but if you but 2 wires in the larger space then derating occurs.
macmikeman
Senior Member
- Location
- Planet macmikeman
Re: cable stackers
Please gentlemen.
Cable stakers have provided us with a neat working solution to a non existant problem that those of us who have to make our living in the field encounter. How about instead of "doing calculations" you actually put your hand on several thousand(no make that millions) runs of cables stacked together under a single staple and see if they are actually ever getting hot. I like stackers because they keep electrical inspectors happy. That is the true use for them.
Please do people a favor and wait for real problems to crop with wiring techniques before we trash them based on some theory or our imaginations going wild.
Please gentlemen.
Cable stakers have provided us with a neat working solution to a non existant problem that those of us who have to make our living in the field encounter. How about instead of "doing calculations" you actually put your hand on several thousand(no make that millions) runs of cables stacked together under a single staple and see if they are actually ever getting hot. I like stackers because they keep electrical inspectors happy. That is the true use for them.
Please do people a favor and wait for real problems to crop with wiring techniques before we trash them based on some theory or our imaginations going wild.
stamcon
Senior Member
- Location
- South San Francisco CA
Re: cable stackers
These are from 3M web site -
"3M? Cable Stackers organizes cable runs and aids in identification; putting an end to tangled wires and the potential heating that could occur when cables are held together tightly under a single fastener."
"The 3M SI-1 cable stacker centers multiple cables on a 2x4 framing member, allowing simplified compliance with article 300-4(d) of the National Electric Code. It organizes cable runs and simplifies identification, putting an end to tangled wires and the potential heating that could occur when cables are held tightly under a single fastener. The SI-1 is made from reclaimed plastic. Installation is easy with cables snapping in for a positive lock. Simplifies compliance with the spacing requirements of the National Electrical Code, article 300-4(d) and the Canadian Electric Code Part I, Section 12-516."
No code section specified, for meeting the requirements regarding "bundled cables".
These are from 3M web site -
"3M? Cable Stackers organizes cable runs and aids in identification; putting an end to tangled wires and the potential heating that could occur when cables are held together tightly under a single fastener."
"The 3M SI-1 cable stacker centers multiple cables on a 2x4 framing member, allowing simplified compliance with article 300-4(d) of the National Electric Code. It organizes cable runs and simplifies identification, putting an end to tangled wires and the potential heating that could occur when cables are held tightly under a single fastener. The SI-1 is made from reclaimed plastic. Installation is easy with cables snapping in for a positive lock. Simplifies compliance with the spacing requirements of the National Electrical Code, article 300-4(d) and the Canadian Electric Code Part I, Section 12-516."
No code section specified, for meeting the requirements regarding "bundled cables".
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