STANDBY GENERATORS

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TOOLPRO

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I HAVE INSTALLED NUMEROUS STANDBY GENERATORS. I NOW HAVE AN INSPECTOR THAT IS TURNING ME DOWN FOR THIS:
ON A 200 AMP METER BASE, INSTALL A SERVICE ENTRY RATED, NEMA3 AUTO. TRANSFER SWITCH NEXT TO METER BASE. WIRE FROM LOAD SIDE OF METER BASE TO TRANSFER SWITCH, THEN TO 200 AMP BREAKER PANEL.
INSPECTOR NOW SAYS:
SINCE THE TRANSFER SWITCH IS NOW CONSIDERED THE FIRST MEANS OF DISCONNECT THE BREAKER PANEL IS A SUB PANEL. 1.THEREFORE YOU MUST SEPARATE ALL YOUR GROUNDS AND NEUTRALS IN BP, 250.24.A5 2. THE GROUNDING ELECTRODE CONDUCTORS MUST TERMINATE IN THE FIRST MEANS OF DISCONNECT. 250.24.A1 3. GROUNDING ELECTRODE CONDUCTORS CANNOT BE SPLICED. 250.64C 4. NEED TO BOND THE GAS LINE 250.104B 5. INTERSYSTEM BONDING TERMINATION REQUIRED 250.94
THERFORE I HAVE TO INSTALL NEW GROUNDING ROS AT PANEL...AS WELL AS THE OTHER LISTED ITEMS. IS THIS INSPECTOR RIGHT?
 
CAPS

CAPS

jumper said:
Welcome. Easy on the caps please. It makes your post hard to read and caps may be considered as yelling.
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Sorry Jumper...I always write in caps....I am not yelling...I know thats what it means. I have to wear cheaters to see..and writing in caps helps me from making spelling errors. Plus sometimes I do not capialize proper nouns...and writing in caps covers that. thx Toolpro
 
Sounds like you have found an inspector that knows his Code.
All the points are valid and after a quick look the references seem correct.
 
TOOLPRO said:
Sorry Jumper...I always write in caps....I am not yelling...I know thats what it means. I have to wear cheaters to see..and writing in caps helps me from making spelling errors. Plus sometimes I do not capialize proper nouns...and writing in caps covers that. thx Toolpro
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Hi TOOLPRO,
On this Forum you can choose to use a larger font size very easily. That makes it easier for you and others at the same time.
Some of our regular members use a large font routinely.
 
No different than setting a remote disconnect and running through the basement of a dwelling to a main lug panel.

Just curious as to how many of these units have been improperly installed?
 
Standby Generators - Residential

Standby Generators - Residential

nizak said:
No different than setting a remote disconnect and running through the basement of a dwelling to a main lug panel.

Just curious as to how many of these units have been improperly installed?
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From my experience the vast majority of these systems have be incorrectly installed! From our service dept. records 90-95% of the units we have been called to service were installed as "Whole House Systems" with the installer cutting the service entrance cable between the meter base and the service panel, inserting the transfer switch, connecting the generator to the transfer switch and gas meter, and calling it "Good to GO".

When you install a "Whole House System" using an SE rated transfer switch, that transfer switch is your "Service Equipment" and ALL panels downstream MUST be wired or rewired as "Sub-Panels" with the Equipment Grounding and Neutral conductors landed on their own respective and separate buss bars. ALL stoves, ovens, cook tops and dryers fed from the sub-panel must be 4 wire with a separate Equipment Grounding conductor.

The following MUST also be done for SE rated transfer switch installations:

A) Your Grounding Electrode conductor MUST connect inside the SE rated transfer switch.

B) Your water pipe bond MUST connect inside the SE rated transfer switch.

C) Your gas pipe bond MUST connect inside the SE rated transfer switch.

D) You must install an Intersystem Bonding (ISB) terminal block.

The second item missed by the installer on almost ALL of the units we are called to service is the fuel supply. Your fuel supply and piping MUST be able to supply 100% of the generator full load fuel requirements PLUS 100% of the fuel requirements of all other gas appliances connected to the system, with all appliances operating at full load.

Gas meters and the fuel piping must be sized using the 1/2" pressure drop column. Most residential natural gas systems were originally sized using the 2" pressure drop column. This WILL NOT WORK for generators! Your fuel system must also meet the following requirements.

A) Your generator fuel supply must run directly from the meter to the generator with NO OTHER gas appliances connected to that line.

B) ALL shutoff valves MUST be of the "Full-Flow type.

C) A drip leg MUST be installed near the generator fuel inlet.

D) The supplied "Flex-Line" MUST be installed at the generator.

E) The supplied "Flex-Line" MUST NEVER be connected directly to the generator. FIRE HAZARD!


Inadequate fuel supply is an INSTALLER ERROR that can possibly damage engine valves, pistons, and cylinder head gaskets. This damage is NOT generally covered under the manufacturer's warranty program.
 
Standby Generators -Gas Line Bond

Standby Generators -Gas Line Bond

A better statement of the gas pipe bonding requirement would have been:

C) Your gas pipe bond MUST connect inside the SE rated transfer switch (If one is required).

Here in Michigan the following is required under State of Michigan Part 8 Electrical Rules.

•Rule 871. Section 250.104(B) of the code is amended to read as follows:
•250.104(B) Corrugated stainless steel tubing (CSST). Listed corrugated stainless steel tubing gas piping systems SHALL be bonded to the electrical service grounding electrode system. The bonding jumper SHALL connect to a metallic pipe or fitting between the point of delivery and the first downstream CSST fitting. The bonding jumper SHALL be not smaller than # 6 copper wire or equivalent. A gas piping system that is bonded pursuant to this section SHALL be considered effectively bonded regardless of the amount of CSST in the system.

On jobs here where the gas piping is black iron the equipment grounding conductor of the circuit energizing the equipment is sufficient to bond the gas piping, however if CSST is used any where on the project the bond noted above MUST be installed. If your AHJ requires a separate gas pipe bond on your project and you are using a "Whole House" SE Rated transfer switch then that conductor MUST be connected inside the service equipment (i.e. SE Rated Transfer Switch).
 
Radioman91 said:
•Rule 871. Section 250.104(B) of the code is amended to read as follows:
•250.104(B) Corrugated stainless steel tubing (CSST). Listed corrugated stainless steel tubing gas piping systems SHALL be bonded to the electrical service grounding electrode system. The bonding jumper SHALL connect to a metallic pipe or fitting between the point of delivery and the first downstream CSST fitting. The bonding jumper SHALL be not smaller than # 6 copper wire or equivalent. A gas piping system that is bonded pursuant to this section SHALL be considered effectively bonded regardless of the amount of CSST in the system.

On jobs here where the gas piping is black iron the equipment grounding conductor of the circuit energizing the equipment is sufficient to bond the gas piping, however if CSST is used any where on the project the bond noted above MUST be installed. If your AHJ requires a separate gas pipe bond on your project and you are using a "Whole House" SE Rated transfer switch then that conductor MUST be connected inside the service equipment (i.e. SE Rated Transfer Switch).
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I'm glad you brought that up. That was one of the exceptions I was going to make to the OP. The other one was splicing the water pipe and rod grounds. Look at this section :

250.62 Grounding Electrode Conductor Material.
(C) Continuous. Except as provided in 250.30(A)(5) and (A)(6), 250.30(B)(1), and 250.68(C), grounding electrode conductor(s) shall be installed in one continuous length without a splice or joint. If necessary, splices or connections shall be made as permitted in (1) through (4):
(1) Splicing of the wire-type grounding electrode conductor shall be permitted only by irreversible compression type connectors listed as grounding and bonding equipment or by the exothermic welding process.
(2) Sections of busbars shall be permitted to be connected together to form a grounding electrode conductor.
(3) Bolted, riveted, or welded connections of structural metal frames of buildings or structures.
(4) Threaded, welded, brazed, soldered or bolted-flange connections of metal water piping.

I've used hi-press crimps on many gen sets and have never been tagged.
 
goldstar said:
I'm glad you brought that up. That was one of the exceptions I was going to make to the OP. The other one was splicing the water pipe and rod grounds. Look at this section :

250.62 Grounding Electrode Conductor Material.
(C) Continuous. Except as provided in 250.30(A)(5) and (A)(6), 250.30(B)(1), and 250.68(C), grounding electrode conductor(s) shall be installed in one continuous length without a splice or joint. If necessary, splices or connections shall be made as permitted in (1) through (4):
(1) Splicing of the wire-type grounding electrode conductor shall be permitted only by irreversible compression type connectors listed as grounding and bonding equipment or by the exothermic welding process.
(2) Sections of busbars shall be permitted to be connected together to form a grounding electrode conductor.
(3) Bolted, riveted, or welded connections of structural metal frames of buildings or structures.
(4) Threaded, welded, brazed, soldered or bolted-flange connections of metal water piping.
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I've used hi-press crimps on many gen sets and have never been tagged.
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Are you splicing an actual GEC or bonding jumpers?
 
infinity said:
Are you splicing an actual GEC or bonding jumpers?
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I generally pull both the water main and rod wires completely out of the existing existing main breaker panel, crimp on new lengths of wires (sized accordingly) and re-feed them to the transfer panel. Am I creating a violation in your opinion ? None of the EI's in my area have a problem with that method.
 
goldstar said:
I generally pull both the water main and rod wires completely out of the existing existing main breaker panel, crimp on new lengths of wires (sized accordingly) and re-feed them to the transfer panel. Am I creating a violation in your opinion ? None of the EI's in my area have a problem with that method.
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Since you have two separate GEC's they would need to be irreversibly spliced when extended. You could just extend one GEC for the water pipe to the new transfer switch and split bolt the existing rods GEC to the water pipe GEC. In that case the conductor to the rods become a bonding jumper and is no longer a GEC. Bonding jumpers do not require irreversible splicing.
 
infinity said:
Since you have two separate GEC's they would need to be irreversibly spliced when extended. You could just extend one GEC for the water pipe to the new transfer switch and split bolt the existing rods GEC to the water pipe GEC. In that case the conductor to the rods become a bonding jumper and is no longer a GEC. Bonding jumpers do not require irreversible splicing.
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That's a good point. I'll remember that for the next gen set I install. The thing is I have so many insulated barrel crimps that I got from the wife of a deceased electrician that I'm sure I can coast out to my retirement and still have plenty of them to spare. I'll probably end up selling whatever I have left at a garage sale. BTW, my wife is scheduled to retire next year but she tells me that I'm going till I drop. I'm hoping to get another 20 years in before I finally walk out on the ice. ;)
 
I did a 400 amp service a while back, new house, double lugs in the meter to two 200a MB Panels. They had a 20kw genny for just one panel. The inspector allowed me to leave the grounding and neutrals together in the panels considering the transfer switch as another panel. So technically the one panel fed from the transfer switch should have been separated. I have seen many times where an additional panel was installed next to a filled up main panel with no ground-neutral separation. Should they be? Should this rule be changed?
 
GerryB said:
I did a 400 amp service a while back, new house, double lugs in the meter to two 200a MB Panels. They had a 20kw genny for just one panel. The inspector allowed me to leave the grounding and neutrals together in the panels considering the transfer switch as another panel. So technically the one panel fed from the transfer switch should have been separated. I have seen many times where an additional panel was installed next to a filled up main panel with no ground-neutral separation. Should they be? Should this rule be changed?
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The second 200a MB panel downstream of your 200a SE Rated Transfer Switch is a sub-panel and MUST have the Neutral and EGC landed on separate buss NOT connected together in the downstream panel. This applies not only to transfer switch/generator installations but to ANY "Sub-Panel" fed downstream from another including the "additional panel installed next to a filled up main panel". 250.24(A)(5)

CAUTION: Dangerous objectionable neutral current will flow on conductive metal parts of electrical equipment as well as metal piping and structural steel, in violation of 250.6(A), if more than one system bonding jumper is installed, or if it’s not located where the grounding electrode conductor terminates to the neutral conductor.

Objectionable neutral current on metal parts can cause electric shock, fires, and improper operation of electronic equipment and overcurrent devices such as GFPs, GFCIs, and AFCIs.
 
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