The Saint Paul globe. (St. Paul, Minn.) 1896-1905, 1901-08-30


/ they are exposed to fyings of easily in
| fammable material should have the car
| bons enclosed completely in a globe in
| such manner as to avoid the necessity
| for spark arresterS.
! Globes and spark arresters will not be
| required in so-called inverted arc
| lamps, but this type of lamp must not
/ be used where exposed to hyingS of cas-
! lily inflann,able materials.
d. Where hanger boards are not used,
/ lamps must be hung from insulating sup
ports other than their conductors.
Is. IncRndescent Lamps in Series
Circuits
a Must have the conductors Installed
| as heretofore provided, and each must be
! provided with an automatic cut-out.
b. Must have each lamp suspended
! from hanger-board by means of rig
| id tube.
c. No electromagnetic devices for
! switches, and no system of multp!e-se-
ries or series multiple lighting will be al
/ lowed
d. Under no circumstances must they
be attached to gas fixtures.
Sec. PSI. Constant Potential Sys-
TENS
1 GENERAL RULEs-ALL VoLTAGES.
10. Automatic Cut-Outs QFuses and
Circuit Breakers)-
a. Must be placed on all service wires,
|
| as possible to the point where they en-
ter, the buildings and inside the walls.
! and arrange TO cut off the entire current
| from the building.
Where the switch required is inside
| the building. the cut-out required by
| this section must be placed so as to pro-
! tect it.
b. Must be placed at every point where
| change is made In the size of wire (un-
| less the cut-out in the larger wire will
protect the snaller).
n Ia 0cln In
| met, or provided with an approved cover
! (See. No. 52). They must not be placed
| in the canopies or shells of fixtures.
Must be readily accessible.
d. Must be SO placed that no set of
| incandescent lamps, whether grouped or
on one fixture or several fixtures or
/ pendants, requiring more than $50 watts
shall be dependent upon one cut-out, ex-
| cept in the cases of large chandeliers,
stage borders and illuminated signs.
e. Must be provided with fuses, the
| rated capacity OF which does not exceed
! the allowable carrying capacity of the
| wires, and when circuit breakers are
| used. they must not be set more than
| about thirty per cent. above the allow
| able carrying capacity of the wire unless
| fusible cut-out is also installed in
the circuit
| 90. Switches
| (See No. 49, and for Construction No51.)
| q. Must be placed on all service wires
| either overhead or underground, in
| readily accessible places, as near as pos
| sible to the point where the wires en-
! ter the building and arrange to cut off
| the entire current
b. Must always be placed In dry, ac-
cessible places, and be grouped as far as
possible. Knife switches must be so
! placed that gravity will tend to open
| rather than close the switches
G. Must not be single pole, except when
| the circuits which they control, supply
not more than six 16-candle power
| lamps, or their equivalent.
d. Where flush switches are used
! whether the conduit system or not, the
switches must be enclosed in boxes con-
| structed of, or lined with fire-resisting
material No push buttons for bells, or
gas lighting circuits. shall be placed in
! the same wall plate with switches con-
/ trolling electric light or power wiring.
| Fl. Electric Heaters
| a. Must, if stationary. be placed in a
! safe situation, isolated from inflammable
| heat.
| b. Must each have a eut-out and in
dicating switch. (See No. Is a.
| c. Must have the attachment of feed
! wires TO the heaters in plain sight, easily
accessible and protected from interior
| ence, accidental or otherwise.
d. The flexible conductors for portable
! apparatus, such as iron, etc, must have
an approved insulating covering. (See No.
! 40 h.
e. Must each be provided with name
| pldIej giving the maker name, ana the
normal capacity in volts and amperes.
Sec. 252. Low Potential SYSTEM
$50 Volts or Less.
Any of the circuit attached to any
/ machine, or combination of machines,
which develop a difference of potential
| between any two wires, or over ten volts
| and less than three hundred volts, shall
! be considered as a low-potential circuit
and as coming under this class, unless an
| approved Transforming device is used,
which cuts the difference of potential
/ down to ten volts or less. The primary
| circuit not to exceed a potential of thir-
/ ty-five hundred volts.
Sec. 253. General Rules
%. Wires
a. Must not be laid in plaster, cement,
! or similar finish.
| b. Must never be fastened with staples.
C. Must not be fshed for any great
distance, and only in places where the
| Inspector can satisfy himself that the
I rules have been complied with
d. Twin wires must never be used, ex-
eept i'll eondutts or where flexible con-
F.. ductors are necessary.
e. Must be protected on side walls from
mechanical injury When crossing floor
timbers in cellers or in rooms where they
might be exposed to injury, wires must
be attached by their insulating supports
to the under side of a wooden strip not
less than one-half inch in thickness and
not less than three inches in vida
Suitable protection on the side wall may
be secured by a substantial boxing re-
tanning an air space of one inch around
the conductor, closed at the TOP (the
wires passing through pushed holes), and
extending not less than one foot from
the floor, or by an iron-armored or metal
sheathed insulating conduit sufficiently
strong to withstand the strain it will be
subject to, or plain metal pipe lined with
Suladng tubing which must extend one
men DeVOnd ha of no
tube
The pipe must extend not less than five
feet above the floor, and may extend
through the floor in place of a floor bush
ing.
If iron pipes are used with alternating
currents the two or more wires OF a cir
cult must be placed in the same conduit.
In this case the insulation of each wire
must be reinforced by a tough conduit
tubing projecting beyond the ends of the
IRON pipe, at least two inches.
T. When rcn Immediately under roofs.
or IN proximity to water pipes or tanks,
viii be considered as exposed to moisture
See. 254. Special Rules
For Open WoriI-In Dry Places.
g. Must have an approved rubber or
slew burning weather proof insulation.
(See Nos. Il and 42)
h. Must be rightly supported on non
ccmhustihle, non absorptive insulatoFs
which separates the wire at least one
half inch from the surface wired over,
and they must be kept apart, at least two
and one-half inches
Rigid supporting requires under ordi-
nary conditions, where wiring along fiat
surfaces, supports at least every four and
one-half feet. If the wires are liable to
be disturbed. the Dis ance between sup
ports should be shortened In buildings
of mill construction mains of 8 B. & S.
wire or over, where not liable to be dis
turbed, may be separated about four
inches from mi her fn iro1la