COMPEX 20.Q Refresher Course Nov-20 Flashcards
1.
Which one of the following is required when carrying out a close inspection of a pressurised Ex pz motor?
an insulation (IR) test of the stator windings
electrical protective devices are set correctly
ducts, pipes and enclosures are in good condition;
electrical protective devices operate within permitted limits
ducts, pipes and enclosures are in good condition
2.
Which one of the following components may be considered simple apparatus for use in an IS circuit?
0.1 kW motor
an L.E.D
a 9V battery
an electronic relay.
an L.E.D
3.
Unused cable cores of multi-cored cables are required to be terminated by which one of the following?
Terminate in unearthed terminals
Cut back and insulate both ends with tape
Connect one end to the neutral conductor
Connect both ends to earth.
Terminate in unearthed terminals
4.
The maximum interval between the periodic inspections of movable electrical equipment (portable and transportable equipment) is?
6 months
1 year
2 years
3-years
1 year
5.
Fault-finding or testing in an hazardous area is permitted when?
A gas-free certificate has been obtained
The equipment is flameproof Ex d
When the area of work has a gas monitor
The equipment is pressurised Ex p
A gas-free certificate has been obtained
6.
For Ex e equipment installed before 2007 which one of the following glands was NOT acceptable?
Ex e certified
Uncertified
Ex d certified
Uncertified plastic.
Uncertified plastic.
7.
Which one of the following statements correctly describes the ‘Temperature class’ ?
The temperature will not be exceeded should fault conditions occur;
The maximum temperature of internal surfaces exposed to a flammable gas;
The average surface temperature of the equipment measured at its hottest
point
The maximum surface temperature of those surfaces exposed to a flammable gas during normal or specific fault conditions.
The maximum surface temperature of those surfaces exposed to a flammable gas during normal or specific fault conditions.
8.
Equipment marked Ex nL is to be considered for use in an intrinsically safe (IS) circuit. Which one of the following will determine if this is possible?
Can be connected in a ‘level ic’ IS circuit if the electrical parameters are the same
It is not suitable for use in an intrinsically safe (IS) circuit
Can be connected in a ‘level ib’ IS circuit if the electrical parameter/are same
If the electrical parameters are the same it may be used in any IS circuit
Can be connected in a ‘level ic’ IS circuit if the electrical parameters are the same
9.
The type of inspection required on the equipment in an installation when handed over from the installer is?
Sample
Initial
Detailed
Visual
Initial
10
Cables for non-intrinsically fixed equipment are required to be thermostatic, thermosetting or elastomeric provided they are?
Circular, compact, have extruded bedding and fillers;
Flat, compact, with extruded bedding and fillers;
Circular, compact, with extruded bedding & fillers are non-conductive
Circular, compact, have extruded bedding, and fillers, if any, are non-hygroscopic.
Circular, compact, have extruded bedding, and fillers, if any, are non-hygroscopic.
11.
Obstruction of the flamepath openings of the flanged joints of Ex d enclosures by solid obstructions requires minimum clearances depending on the equipment group. For a IIC enclosure this not less than?
30mm
40mm
10mm
50mm
40mm
12.
An Ex de IIC, Motor has an Ex e Terminal box fitted. What types of gland can be fitted.
What is the minimum acceptable cable gland if round compact SWA cables with extruded bedding are used?
E1W Ex e gland
E1W Ex e or E1W Ex d gland
E1W Ex d gland
E1W Ex d barrier gland
E1W Ex e or Ex d gland
Gland Markings
A. Outer Seal only
A2. Unarmoured cable with outer seal.
B. Armour lock only.
BW. SWA cable without seal, indoor use.
BARR. Inner barrier seal, outer seal, and armour lock.
C. Outer Seal with armour lock.
CR-C Double compression, barrier gland, SWA, braided cable (Croclock)
CW. Single seal, SWA, outdoor use.
CX. Single seal, braided cable.
D. Inner seal and armour lock.
E. Double seal.
E1W. Double seal, SWA cable, indoor / outdoor.
E1X. Double seal, braided cable indoor / outdoor.
F. Multiple certification.
IE. Integral earth.
L. Lightweight design.
R. Reduced bore size.
T. Pliable wire armour, flexible cables.
W. Steel wire armour (SWA).
X. Wire braid
Y. Aluminium strip wire.
Z. Double steel tape armoured.
E1WF.
Double Seal, SWA, multiple certification
E1W
Double Seal, SWA
E1We
Double Seal, SWA, inner cable seal and outer cable seal.
BARR-W
Barrier gland, SWA or Tape bedding.
13.
The te time of an Ex e motor indicates?
The disconnection time limit when stalled after starting from cold.
The disconnection time limit when stalled after starting from hot.
The run-up time to full speed.
The minimum time interval between re-starts.
The disconnection time limit when stalled after starting from hot.
14.
A visual inspection is defined as an inspection which?
Is carried out prior to equipment being brought into service
Is carried out on some of the equipment
Identifies defects apparent to the eye without using tools or ladders
Includes those aspects covered by a close inspection and which also
identifies those defects only identifiable by opening the enclosure
Identifies defects apparent to the eye without using tools or ladders
15.
Equipment marked Ex d [ia] indicates that?
The flameproof enclosure is deemed ‘simple apparatus’ in an ‘ia’ circuit
The flameproof enclosure contains associated IS equipment
The components inside are all intrinsically safe
Electrical items other than IS items are inside.
The flameproof enclosure contains associated IS equipment
