East Kent Radio Society EKRS
1
Intermediate Course (9) Safety
Karl Davies
Remember the Foundation Slides
2
Soldering - Safety Issues
(Part 1)
3
 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.
Soldering - Safety Issues
(Part 2)
4
 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.
Soldering - Safety Issues
(Part 3)
5
 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.
Workshop Safety - General
(Part 1)
6
 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.
Workshop Safety - Drilling
(Part 2)
7
 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.
Ladders - Safety
8
 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.
4 Metres
 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.
1 Metre
Antenna Installation Safety
9
 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, high
winds, icing, bird strikes
Safety Earthing (Foundation)
10
 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)
Mains Cables
11
 Avoid trailing mains leads on the shack floor - Trip Hazards!
 Same as for Foundation.
 Damage to self.
 Damage to Equipment.
 Cost of Replacement / Repair
Mains Plugs Fitting
12
• FLEX
COLOURS:-LIVE=BROWN,
NEUTRAL=BLUE EARTH=GREEN / YELLOW
• 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
THEEQUIPMENT.
• YOU
WILL HAVE TO WIRE A PLUG HERE
CORRECTLY
Mains Plugs Fitting
13
 Flex Colours:- Live=Brown,
Neutral=Blue Earth=Green / Yellow
 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 here
correctly
Mains Plug Fuses
14
 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.
RCD’s , OFF Switch, Lightning
15
 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.

A residual-current device (RCD), similar to a residual current circuit
breaker (RCCB), (formerly known as an Earth leakage circuit breaker or ELCB)
is an electrical wiring device that disconnects a circuit whenever it detects that
the electric current is not balanced between the energized conductor and the
return neutral conductor.
RF Radiation Issues
16
 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.
http://www.hpa.org.uk/Topics/Radiation/UnderstandingRadiation/InformationSheets/info_AmateurRadio/