T2 industrial
When using Flemings left hand rule the thumb points in the direction of ?
Force exerted on the conductor
An advantage of steel conduit over plastic is
a seperate protective conductor is not required
IS/EN 60309 sockets outlets rated for 230 volt are coloured
Blue
The centrifugal switch of a single phase split phase induction motor is used to
Disconnect the run winding
Steel conduit is available in what sizes
16mm, 20mm, 25mm, 32mm
Where cable or busbar trunking passes through a ceiling it must contain
A fire barrier
Which type of supply produces a sinusoidal waveform
A.C. generator
One of the main functions of a contactor is
Provide no-volt protection
An open circuit on the coil electromagnet has
Infinite resistance and zero inductance
which circuit is regarded as a category B circuit
Fire alarm circuit
The minimum information which should be displayed on a distribution board labelling system is
Circuits controlled
The formula millivolts/amp/meter is used to calculate
Vold drop of a conductor
One factor that does not affect the resistance of a conductor is
The type of insulation of the cable
Compact fluorescent lamps are less expensive to operate than the filament lamps because
Their efficiency is higher with a longer working life
The capacitor connected across the incoming supply terminals in a fluorescent fitting is to
Improve power factor
The voltage between any two phases of a 400v three phase 4 wire supply is
230 volts
The conductors contained in a busbar trunking system are
Bare copper or aluminium bars
The effect that limits the current flow in a pure inductor connected to ans A/C supply is called the
Inductive reactance
When capacitors are connected in series, the applied voltage is
The sum of the voltages across each of the capacitors
Flemings right hand rule is used to determine the direction of field, current and force in a
Generator
The second digit in the IP classification system for enclosures mean
The degree of protection against ingress of water
If one of the supply lines connected to a three phase induction motor becomes disconnected the current through the other two lines will
Increase
To change the direction of a three phase motor it is necessary to change
Any two of the three line conductors
The minimum I.P protection on fittings where water hosing is used is
I.P 45
one of the supply lines to a three phase motor becomes open circuit the voltage through the other two will
Remain the same
B type MCBs will operate magnetically at
3-5 times its rated current
If the capacitor across the mains in a fluorescent fitting becomes disconnected the lamp will
Still function
In relation to cables what does LSF mean
Low smoke and fume
A permanent
Requires no external power force
Lens law states that
An induced EMF will always oppose the effect producing it
The mechanism connecting the rotating windings to the brushes in a DC generator is called
The slip rings
when comparing the heating effect of 10amps RMS AC with 10amps DC the result will be
The same heating effect
The voltage between either current carrying conuctor and earth on the secondary winding of a portable 230V/115V transformer for power tools is
57.5 volts
On a running coupler the exposed threads should be
painted with galvanised spray
The standard supply voktages in ireland are
400v and 230v
Eddy current losses in a power transformer is minimised by
Constructing the core with steel laminations
The main disadvantage of magnesium oxide as an insulator in a cable is that
It absorbs moisture when exposed to the atmosphere
The arc-quenching medium used in HBC fuse
silica sand/quartz
when using a clip on ammeter to check the motor current it is necessary to have the motor
connected to the motor and running
The minimum level of IP protection on all fittings for general areas in a farm installation is
IP44
Which combination of the following is required in order to induce an electrical current.
1. Motion
2.Magnetic field
3. Conductor
4.Voltage
1.2.3
If an iron core is inserted in a solenoid and the current is maintained at a constant value the magnetic flux will
Increase in strength
Earth continuity of metallic trunking can be improved if
Copper earth straps are bolted across all joints
Using flemings r/h or l/h rule the second finger points in the direction of the
current flow
the term GLS means
general lighting service
an advantage if aluminium conductors is
they are lighter than copper
The IP classification system the second digit states
The degree of protection against ingress of water
The earth in transformers used for portable tools is connected to
the centre tap and the iron core of the secondary winding
If the primary winding of a transformer is connected to a DC supply
A voltage would be induced momentarily at 'switch on' and at 'switch off'
Neutral connections in a distribution board are connected in the same sequence as the phase conductors to
assist in circuit testing and fault finding