Chapter XXIV: Appendix: I

The following recommendations were made by the Dangerous Trades Committee of the Home Office. For the purposes of these regulations a station where the direct current generated is at 700 volts or any higher number, or where the alternating current generated is at 350 volts or any higher number, shall be considered a “high pressure station,” and all metal conductors, whether they be on the dynamos, the switchboard, the mains, or any other part of the station carrying a current at a pressure equal to or greater than that above mentioned, shall be deemed to be at “high pressure.”

The Committee recommend that the following regulations should be applied in all those cases mentioned in paragraph 1 where electricity at high pressure is in use. It is not intended that they should be applied to low pressure systems:--

1. The frames and bed plates of all generating machines shall be
efficiently connected to earth.

2. The rails fencing dynamos, or other generating machines,
shall be made of wood or other non-conducting material.

3. All terminals, collecting brushes, main connectors, parts of
dynamos, motors or other appliances, to which neither Regulation
No. (6) nor No. (7) applies, shall be so placed, covered, or
fenced with non-conducting materials, that no person can touch
accidentally, either with his body, clothing, or any conducting
tool, two parts differing from each other by an amount which
constitutes a high pressure. This rule is to be read in
connection with No. 4.

4. The floors of all places where it would be possible to make
connection with metal at high pressure shall be covered with
an insulating mat of suitable material and kept in a state of
efficient insulation.

5. The material use for wiping or cleaning the commutator strips
or collector rings of dynamos, motors, or rotary converters of
any form shall be applied by means of an insulating handle.

6. In switchrooms and on the front of switchboards, the main
switches, main fuses, main terminals, omnibus bars, and all
other metallic parts shall be insulated or arranged in such
manner as to render it impossible for any person by accident or
inadvertence to touch them.

7. The backs of all switchboards shall be kept closed, except
for the purpose of alterations or repairs. When such work
has to be carried on either at the back or at the front of
switchboards, the following regulations shall apply:--

(_a_) No person except a skilled electrician, or a
workman under his personal and immediate supervision,
shall be employed when any part is at high pressure.

(_b_) No extensive or serious repairs shall be
executed upon metal which is at high pressure.

(_c_) Where the alterations or repairs are not of
an extensive or serious character, all metallic parts at
high pressure shall be covered with an insulating cap or
protected by some form of insulating covering, only one
part, or several at the same pressure, to be exposed at
any one time.

8. All switchboards erected after the application of these Rules
shall have, at the back, a clear space of at least four feet.
This space shall not be utilised as a store room or lumber room,
or be obstructed in any manner.

9. Any person at work upon a cable or portion of the mains under
high pressure shall wear indiarubber gloves on both hands.

10. All aerial high pressure conductors in factories or
workshops shall either be insulated over their entire length,
and supported at such frequent intervals that, in the event
of breakage, they shall not come within reach at places where
persons are liable to pass or to be employed, or shall be so
placed and arranged as to comply with the requirements relating
to such wires in streets enjoined by the Board of Trade.

11. The gloves shall be supplied by the occupier, and it shall
be the duty of the manager to see that they are in a proper
state of repair, and are worn by the workpeople.

12. No examinations, repairs, or alterations necessitating the
handling of mains, wires, machines, or other apparatus, shall be
carried on except in cases of urgent necessity while such parts
are under high pressure, and all such work shall be done under
the personal supervision of an electrical engineer or competent
manager or foreman.

13. Where operations are being conducted upon mains from which
the current has been cut off, the switch shall be locked and
precautions taken that it shall not be unlocked except by the
person in charge of the station on his being satisfied that the
danger is at an end.

14. Every vessel used for lubricating purposes shall be so
constructed that it cannot act as a conductor between the hand
and anything touched.

15. Metal transformer boxes shall be efficiently connected to
earth, and so constructed that in the event of “running to
frame” the earth connection will not be broken by the removal of
the fuse box or any other part of the box.

16. Transformer cases, iron ladders, and all permanent metallic
parts contained within the transformer chamber, and not forming
part of the electric circuit, shall be metallically connected
together.

17. All holes in transformer cases, through which high pressure
conductors pass, shall be lined or bushed with suitable and
effective non-conducting material.

18. All high pressure connections within a transformer chamber
shall be so protected with insulating material that it shall be
impossible to touch them.

19. Switches which can be conveniently operated from the outside
for cutting off both the high and low pressure connections of
the transformers shall be fitted in all transformer chambers
erected after the application of these Rules, and in all
existing chambers, unless it is proved to the satisfaction
of Her Majesty’s Chief Inspector of Factories that such an
arrangement would be attended by special difficulty.

20. Each post or support where series arc lighting is employed
shall be provided with means for completely disconnecting the
arc lamps from the mains, without disturbing the action of the
other lamps.

21. All persons engaged in electrical works shall be made fully
aware of the dangerous parts of the machinery, cables, and their
connections, and shall be practically instructed in methods of
artificial respiration--that known as Sylvester’s is both simple
and efficacious. Rules for artificial respiration, and for the
restoration of persons apparently killed or injured, shall at
all times be kept affixed in the station. All persons engaged
in the works shall thoroughly understand these rules and be
capable of putting them into practice. In the event of a person
being rendered unconscious by an electric shock, artificial
respiration shall, on the careful removal of the body from its
electrical contact, be at once resorted to, and a qualified
medical man immediately summoned.

22. All accidents occurring in generating stations or
transformer chambers shall be notified according to the
provision of section 18 of the Factory and Workshop Act, 1895.

* * * * *

The Committee feel that any set of special rules framed for
the safety of the workpeople in this industry must imperfectly
realise their object if a specially qualified person be not
retained to advise the Secretary of State or Her Majesty’s Chief
Inspector of Factories on matters requiring technical knowledge
of electricity.

H. J. TENNANT.
MAY TENNANT.
THOMAS OLIVER, M.D.
C. V. BOYS.
H. P. SMITH.