PVC straps for PVC conduit ?

[goldstar]

I used to always use PVC straps to support PVC conduit until I had several situations where the sun would heat up both the straps and the conduit resulting in the straps snapping off and the conduit left hanging. I've changed over to using metal 2-hole straps and haven't had a call-back since. I recently had a generator install where I ran about 30' of 1" PVC using metal straps to support it. The inspector failed me citing that I had to use PVC straps. After offering my opinion he told me that I'm not supposed to secure the straps too tightly and that both the PVC and the straps need to have the ability to expand and contract. Has anyone else run into this or is it just another NJ thing ? He didn't cite a Code section but if anyone knows if I'm in violation for using metal straps would you please cite a Code section ? Thanks.

I was also cited for not properly securing the whip to the generator. This was a Generac unit that came with a pre-manufactured and installed 5' metallic seal-tight whip and connection box. There was a straight seal-tight connector installed into the bottom of the connection box and an angle connector into the generator. The whip draped down about 18" and then up into a properly secured connection box. The whip was secured on the house side with a strap. Inspector wants me to secure the whip to the generator as well.

Also, (just an FYI) coming down the pike here in NJ are engraved RED phenolic generator warning signs. Using the signs indicated in NEC 700.7 or the ones supplied by the manufacturer apparently are not good enough in many towns. Inspectors claim that the POCO's do not want any signage posted on their meter enclosures and I've come across several townships that now want engraved phenolic generator warning signs firmly secured adjacent to the meter enclosures.

 

[infinity]

Starting in reverse, the sign issue is a big one because it varies from one inspector to the next. According to 702.7 a sign is not required at the meter enclosure. A sign is required at the service equipment of which according to Article 100 the meter enclosure is not. Since the NEC is not specific what type of sign it is open to interpretation and I've been told that many inspectors have been requiring those big red signs that you've mentioned. I recently had a generator inlet box installation approved and it only had the big red sign on the panel in the basement not on the meter outside.

The whip that you've mentioned is to be secured according to 356.30 for LFNC.

Regarding the PVC, I heard that a listed PVC strap is required because it will allow for thermal expansion where as a tightened metallic strap will not. Funny thing is if you run PVC up a pole the POCO will not allow PVC straps. The POCO says that they must be metallic on pole end and on the other end the local inspector wants PVC straps only. This is on the same run of PVC conduit. :roll:

 

[goldstar]

Starting in reverse, the sign issue is a big one because it varies from one inspector to the next. According to 702.7 a sign is not required at the meter enclosure. A sign is required at the service equipment of which according to Article 100 the meter enclosure is not. Since the NEC is not specific what type of sign it is open to interpretation and I've been told that many inspectors have been requiring those big red signs that you've mentioned. I recently had a generator inlet box installation approved and it only had the big red sign on the panel in the basement not on the meter outside.

Thanks for your reply. As per Generac's instructions one of the signs that they issue indicates that it should be placed on the meter pedestal (whatever that means) in 3 languages.

The whip that you've mentioned is to be secured according to 356.30 for LFNC

.
What part of this am I missing ? The whip is 6' or less. I've never had to secure a whip to an air conditioner condenser unit.

356.30 Securing and Supporting. Type LFNC-B shall be
securely fastened and supported in accordance with one of
the following:
(1) Where installed in lengths exceeding 1.8 m (6 ft), the
conduit shall be securely fastened at intervals not exceeding
900 mm (3 ft) and within 300 mm (12 in.) on
each side of every outlet box, junction box, cabinet, or
fitting.
(2) Securing or supporting of the conduit shall not be required
where it is fished, installed in lengths not exceeding
900 mm (3 ft) at terminals where flexibility is
required, or installed in lengths not exceeding 1.8 m
(6 ft) from a luminaire terminal connection for tap conductors
to luminaires permitted in 410.117(C).
(3) Horizontal runs of LFNC supported by openings through
framing members at intervals not exceeding 900 mm
(3 ft) and securely fastened within 300 mm (12 in.) of
termination points shall be permitted.
(4) Securing or supporting of LFNC-B shall not be required
where installed in lengths not exceeding 1.8 m
(6 ft) from the last point where the raceway is securely
fastened for connections within an accessible ceiling to
luminaire(s) or other equipment

Regarding the PVC, I heard that a listed PVC strap is required because it will allow for thermal expansion where as a tightened metallic strap will not. Funny thing is if you run PVC up a pole the POCO will not allow PVC straps. The POCO says that they must be metallic on pole end and on the other end the local inspector wants PVC straps only. This is on the same run of PVC conduit.

You may be correct but I envision a 30' run of PVC either falling off the siding in 6 months or looking like it ran down the wall like a snake.

 

[ptonsparky]

Plastic straps allow the PVC to move. Especially after a couple years when most of them are broken.

 

[ceb58]

Look at 352.30 (A) & (B) and also 352.44

 

[infinity]

.
What part of this am I missing ? The whip is 6' or less. I've never had to secure a whip to an air conditioner condenser unit.

356.30 Securing and Supporting. Type LFNC-B shall be
securely fastened and supported in accordance with one of
the following:
(1) Where installed in lengths exceeding 1.8 m (6 ft), the
conduit shall be securely fastened at intervals not exceeding
900 mm (3 ft) and within 300 mm (12 in.) on
each side of every outlet box, junction box, cabinet, or
fitting.
(2) Securing or supporting of the conduit shall not be required
where it is fished, installed in lengths not exceeding
900 mm (3 ft) at terminals where flexibility is
required, or installed in lengths not exceeding 1.8 m
(6 ft) from a luminaire terminal connection for tap conductors
to luminaires permitted in 410.117(C).
(3) Horizontal runs of LFNC supported by openings through
framing members at intervals not exceeding 900 mm
(3 ft) and securely fastened within 300 mm (12 in.) of
termination points shall be permitted.
(4) Securing or supporting of LFNC-B shall not be required
where installed in lengths not exceeding 1.8 m
(6 ft) from the last point where the raceway is securely
fastened for connections within an accessible ceiling to
luminaire(s) or other equipment

It's 6' or less' but is it more than 3'?

 

[goldstar]

I'm not in agreement but thought I'd post this before photo before I go back in 6 months and re-install the metal straps



This is what the whip looked like before I strapped it to the generator



and this is after



This is what's coming down the pike in NJ. Engraved phenolic name plates adjacent to outdoor meters. POCOs don't want any self-adhesive decals on their meter enclosures.

 

[ceb58]

Your sign doesn't comply with 702.7(A)

 

[cowboyjwc]

Your sign doesn't comply with 702.7(A)

Correct.

"A sign shall be placed at the service entrance equipment that indicates the type and location of on site optional standby power sources."

So if you thought that the inspector was incorrect and that you didn't need to secure the flex per the section you quoted, then why did you put a strap on the end by the disconnect switch? You only don't have to secure it if you are attaching it to a luminaire.

 

[infinity]

This is what's coming down the pike in NJ. Engraved phenolic name plates adjacent to outdoor meters. POCOs don't want any self-adhesive decals on their meter enclosures.

Why a sign adjacent to the meter? Who is requiring these?

 

[jap]

So if you thought that the inspector was incorrect and that you didn't need to secure the flex per the section you quoted, then why did you put a strap on the end by the disconnect switch? You only don't have to secure it if you are attaching it to a luminaire.

Maybe to deter a Trashcan thief. If the gas line did'nt trip him up, surely the flex would.

 

[PowerSupportElec]

Starting in reverse, the sign issue is a big one because it varies from one inspector to the next. According to 702.7 a sign is not required at the meter enclosure. A sign is required at the service equipment of which according to Article 100 the meter enclosure is not. Since the NEC is not specific what type of sign it is open to interpretation and I've been told that many inspectors have been requiring those big red signs that you've mentioned. I recently had a generator inlet box installation approved and it only had the big red sign on the panel in the basement not on the meter outside.

I've never put a sign up for any interlock/inlet or transfer panel/inlet installation that I've done. No inspector mentioned it, they all passed the work. I never looked into it, I heard about it but thought it was only for automatic generators.

 

[kwired]

Getting back to the PVC straps on PVC conduit, where does it say support method for PVC raceway must be listed? I find nothing.

There is this:

352.30 Securing and Supporting.


PVC conduit shall be installed as a complete system as provided in 300.18 and shall be fastened so that movement from thermal expansion or contraction is permitted. PVC conduit shall be securely fastened and supported in accordance with 352.30(A) and (B).
(A) Securely Fastened. PVC conduit shall be securely fastened within 900 mm (3 ft) of each outlet box, junction box, device box, conduit body, or other conduit termination. Conduit listed for securing at other than 900 mm (3 ft) shall be permitted to be installed in accordance with the listing.
(B) Supports. PVC conduit shall be supported as required in Table 352.30. Conduit listed for support at spacings other than as shown in Table 352.30 shall be permitted to be installed in accordance with the listing. Horizontal runs of PVC conduit supported by openings through framing members at intervals not exceeding those in Table 352.30 and securely fastened within 900 mm (3 ft) of termination points shall be permitted.

But it doesn't say you must use a PVC strap or use a strap listed for use with PVC. Whatever you do use must allow for movement from thermal expansion. I would say that even means where run through holes bored in framing members that means don't make the holes so tight that you need to beat the pipe to install it, make them large enough it fits loose enough to move.

ETA:

There is also this:

352.6 Listing Requirements.

PVC conduit, factory elbows, and associated fittings shall be listed.

Is a strap considered a fitting? If so then what I said before is invalid.

 

[Smart $]

...
Is a strap considered a fitting? If so then what I said before is invalid.

Fitting is defined in Article 100...

Fitting. An accessory such as a locknut, bushing, or other
part of a wiring system that is intended primarily to perform
a mechanical rather than an electrical function.

The defintion leaves it wide open to interpretation.

 

[kwired]

Fitting is defined in Article 100...



The defintion leaves it wide open to interpretation.

I just read that shortly after last posting, and I agree on the interpretation.

 

[goldstar]

So if you thought that the inspector was incorrect and that you didn't need to secure the flex per the section you quoted, then why did you put a strap on the end by the disconnect switch? You only don't have to secure it if you are attaching it to a luminaire.

It all has to do with getting paid. I can agure this point with the inspector and win the battle but I might end up losing the war in the end. I could have taken this to the State DCA and had one of their inspectors come out to do the inspection but that's another vig that I'd have to pay for. Meanwhile, my customer still owes me a final payment and aside from the fact that I now look like the south end of a north-bound horse to them because this inspector decided to cite me for these chicken &*!t violations I just went ahead and put up the sign he recommended I use.

 

[goldstar]

Your sign doesn't comply with 702.7(A)

The one on the inside does. This sign complies with this inspector's requirement and I get paid after he re-inspects. Believe me, this goes against my grain but I currently have too much outstanding $$ right now that I can't afford this fight at the moment. Once I get all my ducks in a row I will write to the State and file a compliant.

 

[goldstar]

Why a sign adjacent to the meter? Who is requiring these?

I checked with several of my fellow electricians who work in Bergen County and they've had to provide these in Tenafly, Dumont, Old Tappan and Paramus to name a few townships. The nameplates are being sold at several local supply houses