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Search took 3.68 seconds. Search: Posts Made By: jim dungar
Forum: Electrical Calculations/Engineering Yesterday, 08:49 PM
Replies: 5
Views: 91
Posted By jim dungar
Utility 'distribution' systems are not subject to...

Utility 'distribution' systems are not subject to the NEC, but you might find something in the NESC.
I think it would be more of a protective relaying issue more than any thing else.
Forum: NEC Yesterday, 08:40 PM
Replies: 7
Views: 84
Posted By jim dungar
Yes, you may always use NEMA Type 12 instead of...

Yes, you may always use NEMA Type 12 instead of Nema Type 1 enclosures. Nema 12 enclosures meet all of the requirements of Nema 1.
Forum: Electrical Calculations/Engineering Yesterday, 05:16 PM
Replies: 5
Views: 88
Posted By jim dungar
Square D says "The curves are more accurate for...

Square D says "The curves are more accurate for high currents than for low currents. In particular, overload currents below 300% may yield different trip times. Conditions in the field may differ...
Forum: Safety Yesterday, 04:46 PM
Replies: 24
Views: 509
Posted By jim dungar
OSHA does not explicitly state the step to...

OSHA does not explicitly state the step to follow, so you will not find a "you can or cannot" in their general standards. It is not weaselwording.

The law says that each employer must create their...
Forum: Safety Yesterday, 11:43 AM
Replies: 24
Views: 509
Posted By jim dungar
The general OSHA standards do not explicitly...

The general OSHA standards do not explicitly state exact steps that must be followed in a LOTO program as it is up to each employer to develop their own policies. However, 1910.147 APP A does list an...
Forum: Electrical Calculations/Engineering Yesterday, 11:33 AM
Replies: 5
Views: 88
Posted By jim dungar
As Zog said, more info is needed. But,...

As Zog said, more info is needed.

But, there is almost no reason to look at the actual trip curve of an interchangeable 'thermal unit' for an overload relay.
Forum: Electrical Calculations/Engineering 11-19-2009, 10:14 AM
Replies: 2
Views: 86
Posted By jim dungar
150°C is also a possibility.

150°C is also a possibility.
Forum: Electrical Contracting and Estimating/Management 11-18-2009, 10:37 AM
Replies: 42
Views: 1,406
Posted By jim dungar
Two levels of quality control are actually fairly...

Two levels of quality control are actually fairly easy to achieve.

Say a machine makes items that are 99% perfect at a rate of 200/hour, and if the machine is sped up to 300/hour the quality...
Forum: Safety 11-18-2009, 10:30 AM
Replies: 24
Views: 509
Posted By jim dungar
A bump test meets the OSHA requirements for LOTO...

A bump test meets the OSHA requirements for LOTO when 'mechanically' servicing the equipment. A bump test is not a sufficient LOTO test for an NFPA 70E 'electrical' de-energization of the equipment....
Forum: Electrical Contracting and Estimating/Management 11-17-2009, 10:45 PM
Replies: 42
Views: 1,406
Posted By jim dungar
A Square D QOxxxGFIC is identical to a QOxxxGFI...

A Square D QOxxxGFIC is identical to a QOxxxGFI breaker. The "C" means it was sold to/through an outlet that caters to consumers (i.e. a home center). They identify their Consumer Product shipments...
Forum: NEC 11-17-2009, 10:37 PM
Replies: 34
Views: 654
Posted By jim dungar
Square D Homeline and QO have the same internal...

Square D Homeline and QO have the same internal guts. The 15 and 20A 1-pole breakers are designed with an "exclusive Qwick-Open" mechanism that begins to open around 6x rating and clears in 1/60th of...
Forum: Electrical Calculations/Engineering 11-17-2009, 10:26 PM
Replies: 38
Views: 802
Posted By jim dungar
Only if you are starting from a 480Y/277V system....

Only if you are starting from a 480Y/277V system.

A single phase 480:480 transformer, like the OP asked about, could be used to create a 480 2-wire secondary which could then be treated the same...
Forum: Electrical Calculations/Engineering 11-17-2009, 02:40 PM
Replies: 27
Views: 575
Posted By jim dungar
Because utilities are usually required to keep...

Because utilities are usually required to keep spare transformers on-hand, they are reluctant to provide a special %Z. However, customers are usually able to purchase 'primary' power and then use,...
Forum: Electrical Calculations/Engineering 11-17-2009, 11:18 AM
Replies: 27
Views: 575
Posted By jim dungar
Most likely the difference is simply the bracing...

Most likely the difference is simply the bracing of the vertical bus bars in each section. 22k SCA bracing was very common on MCCs until the early '80s, but most manufacturers had an option for...
Forum: Electrical Calculations/Engineering 11-17-2009, 10:27 AM
Replies: 27
Views: 575
Posted By jim dungar
Technically, yes a "series combination rating" is...

Technically, yes a "series combination rating" is for protective devices. However it is possible to have an upstream current limiting device protect lower rated 'non-active' components like bus bars...
Forum: Power Quality & Surge Protection 11-17-2009, 12:44 AM
Replies: 3
Views: 145
Posted By jim dungar
When ever you feel like it. Unless you are...

When ever you feel like it. Unless you are running a data center server room, there is almost no need to treat 'computers' in any special way. The old reasons for ground isolation have all but...
Forum: Electrical Contracting and Estimating/Management 11-17-2009, 12:40 AM
Replies: 42
Views: 1,406
Posted By jim dungar
The "C" means this particular product was...

The "C" means this particular product was intended to be sold through Square D's 'Consumer Products' group (i.e. home center) rather than through a 'traditional' full-line distributor.
Forum: Electrical Calculations/Engineering 11-16-2009, 06:04 PM
Replies: 3
Views: 149
Posted By jim dungar
Most likely your equipment contains input...

Most likely your equipment contains input circuits that reference their chassis, which is probably bonded to the grounding conductor. These circuits cause current >5mA to flow on the green wire,...
Forum: Electrical Calculations/Engineering 11-16-2009, 05:59 PM
Replies: 25
Views: 275
Posted By jim dungar
Yes, the secondary will "fry". Primarily,...

Yes, the secondary will "fry".
Primarily, because it belongs to the POCO, but also because it is 'outside' the building it is not a concern according to the NEC.
Forum: NEC 11-16-2009, 04:26 PM
Replies: 9
Views: 257
Posted By jim dungar
If your ATS is not "service entrance"rated, are...

If your ATS is not "service entrance"rated, are the devices in the ATS actual breakers or are they molded case switches?
If they are 'breakers' are they listed (i.e. UL489) and intended to provide...
Forum: Electrical Calculations/Engineering 11-16-2009, 01:00 PM
Replies: 27
Views: 575
Posted By jim dungar
I do not consider, reactors to be a common...

I do not consider, reactors to be a common solutions, although they are often discussed. I have never spec'ed one and have never even seen one installed.

Back in the early 70's, series...
Forum: Electrical Calculations/Engineering 11-16-2009, 12:34 AM
Replies: 6
Views: 190
Posted By jim dungar
Yep.......................................

Yep.......................................
Forum: Continuing Education (CEU) 11-15-2009, 02:50 PM
Replies: 3
Views: 105
Posted By jim dungar
The TEST button is the only "official" way to...

The TEST button is the only "official" way to test these breakers, per UL.
Forum: Safety 11-13-2009, 03:09 PM
Replies: 11
Views: 287
Posted By jim dungar
For sure. Woodhead, Hubbell, and others all...

For sure.

Woodhead, Hubbell, and others all make 'pendant' boxes that contain a type of cord grip that is not a hub.
Forum: Continuing Education (CEU) 11-13-2009, 03:05 PM
Replies: 13
Views: 316
Posted By jim dungar
I always thought STAy KONnected.

I always thought STAy KONnected.
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