six motions of the hand [RE-wrenches]

[mlafferty at universalenergies.com]

Darryl T Wrote:

> The inspector wants no more than 6 motions of
> the to the Solar related equipment.  And wants
> all of these six motions grouped together.  
--snip--

All:

The dreaded "No more than six disconnects" rule!  I personally agree
with the intent to minimize the number of and group disconnecting means
for all sources of power supplying a building, but the Code is specific
on 

Depending on the system configuration, this can get complex, if not
impossible.  Based on Darryl's reference to the 250 Amp breakers, I am
assuming that the solar system has two battery banks, probably two
inverters, and an array of unknown size.  I don't know if there is a
genset, wind, or grid connection also supplying the electrical system,
which would have to have service disconnecting provisions as well.
Following is one approach to deal with this situation... (Caution: This
is a slippery slope!  For pure grid-connected PV systems, I do not
recommend this approach!)

NEC 2002 (For the record, all NEC references here are 2002)
230.71 Maximum Number of Disconnects.
(A) General. The service disconnecting means for each service permitted
by 230.2, or for each set of service-entrance conductors permitted by
230.40, Exception Nos. 1, 3, 4, or 5, shall consist of not more than six
switches or sets of circuit breakers, or a combination of not more than
six switches and sets of circuit breakers, mounted in a single
enclosure, in a group of separate enclosures, or in or on a switchboard.
There shall be no more than six sets of disconnects per service grouped
in any one location. <snip>


230.71 clearly states that the "six disconnect rule" is applied to each
service and set of service-entrance conductors... 1 service = up to 6
disconnects; 2 services = up to 12 disconnects, etc.  Don't build it so
that you have more than you really need... If you can't get it all shut
off with 12 disconnects, well, never mind... Also, the disconnects
specific to each service must be grouped.

In Darryl's case, each of the components listed could technically be
considered a separate service with "different characteristics" as
allowed by 230.2(A)(5) and 230.2(D), printed below.


230.2 Number of Services.
A building or other structure served shall be supplied by only one
service unless permitted in 230.2(A) through (D). For the purpose of
230.40, Exception No. 2 only, underground sets of conductors, 1/0 AWG
and larger, running to the same location and connected together at their
supply end but not connected together at their load end shall be
considered to be supplying one service.

(A) Special Conditions. Additional services shall be permitted to supply
the following:   
(1)	Fire pumps 
(2)	Emergency systems 
(3)	Legally required standby systems 
(4)	Optional standby systems 
(5)	Parallel power production systems

<B&C omitted for irrelevance>

(D) Different Characteristics. Additional services shall be permitted
for different voltages, frequencies, or phases, or for different uses,
such as for different rate schedules.
<snip>


Darryl, I would start with coffee and doughnuts at your meeting on
Friday.  Jelly doughnuts!  As soon as the inspector has a mouthful, ask
him how many services he sees.  (By waiting until he has a mouthful, his
answer will be shorter...)

My guess, based on experience, is that he sees 1 or maybe 2.  He also is
most likely interpreting the "rule" as follows: "No more than six
disconnects to disconnect all sources of power from a building or
structure." instead of "six disconnects per service", from 230.71.  

Have your book ready with 230.2, 230.40, & 230.71 marked, but don't hit
him over the head with it just yet.  I generally research and memorize
the points and language I want to use and just discuss them without
pulling out the book.  I've found that as long as I'm specific and use
the language properly, the little light of recognition generally comes
on in their eyes.  This allows them to have the feeling that they've
"just learned something new" without getting into an argument.

Get him to buy into 230.2(A)(5) and 230.2(D) first... You have multiple
services... (Depending on the configuration and layout, you might
consider the AC as one and the DC as another for instance... The
batteries may be another... You will have to figure out what works for
your situation.)

Once he accepts that there are multiple services, explain that each
service must have six or less disconnects and that they must be grouped.


Give him another doughnut and find out how you can make your application
meet these requirements, if it doesn't already.

Two cents and Good Luck!

Matt Lafferty
Universal Energies Institute
mlafferty at universalenergies.com
(916) 422-9772
(916) 628-7694 Cell
(916) 914-2247 Fax
www.universalenergies.com

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