3005 MEN, SELV, PELV 03 - MEN Refresher questions 2

Reason One for low Earth Fault Loop Impedance is ...

• It reduces the amount of voltage that would flow through a person if there is an earth fault

• It provides for low PSCC which means its safer for persons and property

• It reduces the amount of current that would flow through a person if there is an earth fault

• It ensures that most of the current would flow through a person instead of the PEC

Reason two for Low Earth Fault Loop impedance is ...

• Large amounts of phase and neutral current will flow and cause the protection device to disconnect the faulty circuit quickly

• Large amounts of earth fault voltage will flow and cause the protection device to disconnect the faulty circuit quickly

• Large amounts of earth fault current will flow and cause the protection device to connect the faulty circuit quickly

• Large amounts of earth fault current will flow and cause the protection device to disconnect the faulty circuit quickly

A person who receives a shock of about 20mA for 400ms will usually get no _______ physiological effects but may feel ______ contraction

(a)  

A tunnel type connection on a neutral or earth bar must either have two screws or a screw diameter not less than __% of the ______ diameter

(a)  

The main earthing and equipotential bonding conductors need to be tested and the result of the test must be less than (a)   ohms

The maximum resistance of a PEC is dependant on the type and rating of the __________ _____ and the impedance of the live conductors that comprise the circuit.

(a)  

The __________ __________ test is checking tha the unsulation between the conductors in the installation is intact.

(a)  

(a)   testing is completed to ensure there are no incorrect connections of the active, neutral and earthing conductors

The maximum earth fault loop impedance permitted on a 230v circuit with a C type 16 Amp MCB is how many ohms?

• 5.11

• 3.07

• 1.92

• 1.53

The maximum earth fault loop impedance permitted on a 230v circuit with a C type 50 Amp MCB is how many ohms?

• 0.96

• 0.77

• 0.61

• 0.49