Transcript Intermediate Course

Chelmsford Amateur Radio Society
Intermediate Course
(9) Safety
Chelmsford Amateur Radio Society
Intermediate Licence Course
Christopher Chapman G0IPU
Slide Set 2: v1.3 30-Apr-2009
(9) Safety
1
Remember the
Foundation Slides
Chelmsford Amateur Radio Society
Intermediate Licence Course
Christopher Chapman G0IPU
Slide Set 2: v1.3 30-Apr-2009
(9) Safety
2
Soldering - Safety Issues
(Part 1)
•
The soldering iron stand is a
safe place to keep the iron
when hot.
•
This minimises risk of skin
contact and burns.
•
It often also prevents the iron
overheating when not in use.
Chelmsford Amateur Radio Society
Intermediate Licence Course
Christopher Chapman G0IPU
Slide Set 2: v1.3 30-Apr-2009
(9) Safety
3
Soldering - Safety Issues
(Part 2)
•
The fumes from soldering,
usually the heated flux,
can cause respiratory
problems, especially for
asthmatics.
•
The work bench must be
kept well ventilated to
minimise the inhalation of
the fumes.
Chelmsford Amateur Radio Society
Intermediate Licence Course
Christopher Chapman G0IPU
Slide Set 2: v1.3 30-Apr-2009
(9) Safety
4
Soldering - Safety Issues
(Part 3)
•
Goggles or suitable glasses should be worn when soldering to
prevent solder splashed and spitting flux causing eye damage.
• Note: This will also be mandatory on this course.
Chelmsford Amateur Radio Society
Intermediate Licence Course
Christopher Chapman G0IPU
Slide Set 2: v1.3 30-Apr-2009
(9) Safety
5
Workshop Safety - General
(Part 1)
•
Use tools carefully.
•
Clear tidy work place.
•
Work away from the hands or
body in case of slips.
•
Items being worked on, must
be securely held to prevent it
moving when being drilled,
sawn or filed.
Chelmsford Amateur Radio Society
Intermediate Licence Course
Christopher Chapman G0IPU
Slide Set 2: v1.3 30-Apr-2009
(9) Safety
6
Workshop Safety - Drilling
(Part 2)
•
A chuck key left in the chuck can cause
serious injury to self or others in the
room or nearby.
•
Before drilling a hole use a centre punch.
•
This has a safety implication as well as
aiding neat workmanship.
•
Any activity, especially drilling, can
throw up swarf. This can cause cuts
and eye damage.
•
Suitable precautions such as Goggles
or suitable glasses should be worn.
Chelmsford Amateur Radio Society
Intermediate Licence Course
Christopher Chapman G0IPU
Slide Set 2: v1.3 30-Apr-2009
(9) Safety
7
•
Take care when erecting ladders etc.
•
The correct angle can be expressed as a 1:4 ratio
•
Ladder should be suitably secured at the top or
held at the bottom by an adult.
•
Over-reaching can cause a fall or cause the ladder
to slip, rotate.
•
Use a tool belt to carry tools this will help prevent
falling objects.
•
Wear hard hats when working at height or when
others are working at height.
4 Metres
Ladders - Safety
1 Metre
Chelmsford Amateur Radio Society
Intermediate Licence Course
Christopher Chapman G0IPU
Slide Set 2: v1.3 30-Apr-2009
(9) Safety
8
Antenna Installation Safety
•
Electric shock can result from Antennas and
Ladders coming into contact with, or arcing
from overhead power lines.
•
Even wooden ladders are dangerous in this
context.
•
A wet wooden ladder will conduct electricity.
•
Antennas and feeders must be kept well clear.
•
Feeders / antennas must be soundly fixed in
case of being accidentally being pulled by
high winds, tree branches, icing, birds etc
Chelmsford Amateur Radio Society
Intermediate Licence Course
Christopher Chapman G0IPU
Slide Set 2: v1.3 30-Apr-2009
(9) Safety
9
Safety Earthing (Foundation)
•
Ensure shack equipment is run from a common mains earth to
prevent earth loops - use filtered mains boards and ferrite rings
correctly.
•
Modern Gas & Water Pipes can give high resistance earth.
•
Beware of House earths above earth potential
•
Do not mix Mains Earth (for safety) with RF Earths (for Antennas)
Chelmsford Amateur Radio Society
Intermediate Licence Course
Christopher Chapman G0IPU
Slide Set 2: v1.3 30-Apr-2009
(9) Safety
10
Mains Cables
•
Avoid trailing mains leads on the shack floor - Trip Hazards!
•
Same as for Foundation . . .
– Avoid Damage to Self.
– Prevent Damage to Equipment.
– Avoid Costs of Replacement / Repair
Chelmsford Amateur Radio Society
Intermediate Licence Course
Christopher Chapman G0IPU
Slide Set 2: v1.3 30-Apr-2009
(9) Safety
11
Mains Plugs Fitting
•
Flex Colours:Neutral=Blue
•
Avoid whiskers, trapped wires, and
ensure that Cord Grips are secure, but
don’t pierce the insulation.
•
Fuses are to protect the equipment
and you.
•
ALWAYS FIT THE RIGHT FUSE
FOR THE EQUIPMENT
•
You will have to wire a plug
on the course correctly
Chelmsford Amateur Radio Society
Intermediate Licence Course
Live=Brown,
Earth=Green / Yellow
Christopher Chapman G0IPU
Slide Set 2: v1.3 30-Apr-2009
(9) Safety
12
Mains Plug Fuses
•
The fuse must blow first
•
Not all faults are short circuits
•
So the fuse must blow before causing a fire.
•
Either in the cable or the equipment
•
A 1 Amp panel mounted fuse may protect the
equipment, but what fuse is in the plug
to protect the cable?
•
Recall P=VI or I=P/V
Formula for correct fuse is Current = Power/230
•
A 1A current passing through the body may well be
fatal before the fuse blows.
Chelmsford Amateur Radio Society
Intermediate Licence Course
Christopher Chapman G0IPU
Slide Set 2: v1.3 30-Apr-2009
(9) Safety
13
RCD’s , OFF Switch,
Lightning
•
The shack should be protected by an RCD and a well known
OFF switch, known to all in the house.
•
These operate much faster than a fuse and are much more
sensitive to fault conditions, hence providing better protection
against electrocution.
•
Any external use of mains power MUST use an RCD.
•
Lightning - Disconnect your Antennas !
•
A nearby strike can also be dangerous to you / equipment.
Chelmsford Amateur Radio Society
Intermediate Licence Course
Christopher Chapman G0IPU
Slide Set 2: v1.3 30-Apr-2009
(9) Safety
14
RF Radiation Issues
•
•
•
•
Strong fields from antenna and feeders cause energy to be absorbed
by the body, cause heating as in a microwave oven.
RF burns can be painless at the time and are only apparent after the
event when the damage is done.
The eyes are particularly susceptible since there is no cooling from
the blood supply.
Standing in front of high gain antennas or looking down waveguides
are actions most likely to risk over exposure - Don't !!
Dont Panic
•
•
The HPA and ICNIRP produce guidelines on safe exposure levels
See HPA “Investigation levels” document which gives guidance
on limits, above which a more detailed investigation is required to
ensure the levels are acceptable. See - http://www.hpa.org.uk/
Chelmsford Amateur Radio Society
Intermediate Licence Course
Christopher Chapman G0IPU
Slide Set 2: v1.3 30-Apr-2009
(9) Safety
15