HT UG CABLE LAYING - IMPORTANT DATA

Clearance from other cables :-

1. Power cable to Power cable             -      Clearance is not necessary. However, larger 
                                                                       clearance  better would be current carrying capacity.

2. Power cable to control cable                           -      0.2 metre

3. Power cable to communication  cable            -      0.3 metre

4. Power cable to Gas / Water main                   -      0.3 metre

5. Power cable should not be laid above the telecom cable.

6. Size of the protection pipe (G.I) for the UG cable should be at least 1.5 times the outer dia. of
    the cable. 


For  laying of HT UG 11KV , 3 core, Aluminium, armoured, XLPE  cable :-

Approx. Dia.                                     =       75 cm

Approx. weight                                 =       634 kg

Bending Radius                                =       15 X Dia.

Minimum depth in laying Trench  =       0.9 m

Cable route indicator for every 200 m and also at turning points.

Sand Filling min.  75 mm  at the trench bottom and 75 mm additional covering.

 

Electrical fault prediction device - THERMAL IMAGER

Thermal Imager is the most powerful device to predict the Electrical faulty area without opening the cover of the panel / motor etc.

 

Thermal Imagers are handheld device; used for preventive and predictive maintenance, equipment troubleshooting, repair verification, building inspections, restoration and remediation work, energy audits, and weatherization purposes.

 

The temperature measurement range starts at -20 °C, and goes up to +600 °C. Thermal imagers have IR-Fusion technology.

 

Thermal and visual images are displayed on the Imager LCD and can be saved to a removable SD memory card. Transferring images to a PC is accomplished by removing the SD memory card and connecting it to a PC through the included, multi-format USB card reader. Software is included for image analysis and report generation from these saved images.

 

Thermal Imager power is supplied by one of two included, field-swappable, rechargeable Lithium-ion smart battery packs, with continuous operation.

 

In addition to the features mentioned above, the Imagers provide voice recording capabilities for annotating saved images, emissivity correction, reflected background temperature compensation, transmission correction, and many other useful, easy-to-use features.

 

• Some of the popular brands of Thermal Imager are Fluke & Amprobe.

 

Most Useful Electrical Testing Equipments - Cable and Pipe Locator

Cable and Pipe Locator :-

This instrument traces underground conductive networks such as water and gas mains, telephone, cable TV, and electric power cables. It determines buried lines depth and locates underground metallic masses such as valve caps and manhole covers.
 

To locate and trace an underground metallic line, the line is energized with a radio-frequency signal generated by the transmitter and then detected by the receiver. Inductive or conductive modes of operation are available.

 

The inductive operational mode does not require direct mechanical line connection. The transmitter can energize a buried line without the need to uncover it. Just place the transmitter on the ground or pavement above the line which, once induced with the transmitted signal, retransmits the signal through the ground and air in a pattern that corresponds to its path. The line carries the signal several hundred yards depending on its depth, the mineralization and conductivity of the soil, and the transmitter power setting.

 

The conductive mode of operation requires the line to be exposed so that a direct connection can be made. Conductive energizing is preferred over inductive energizing because it results in more highly defined signal coupling. The signal generated does not spread to other conductive lines in the vicinity of the traced line. Using a ground rod with the direct connection increases the energizing efficiency and, therefore, the length of line that can be traced.

 

Two methods of receiving the transmitted signal are peak detection and null detection. The method used depends on the placement of the receiver. When held at a right angle to the surface of the ground and moved back and forth across the line to be traced, the receiver detects peaks (maximum signals) when directly above the line. When the receiver is held so its face is parallel to the surface of the ground and moved back and forth across the line, the detection of minimum signal or null (absence of signal) indicates that the line is directly below.

 

Most Useful Electrical Testing Equipments - Clamp Earth Tester

Clamp Earth Tester :-

 

Stake-less testing is one of many methods of measuring earth electrode resistance. However what sets this method apart from all other earth electrode test methods is that it is the only method that does not require the use of auxiliary test electrodes or test leads. Since many earth electrodes are in locations surrounded by concrete or tarmac this is of real benefit. The lazy-spike method works well, but can easily be influenced by steel reinforcement or buried metal pipes. Using this clamp earth tester, it is very easy to measure the resistance of earth / ground electrode without disconnecting the electrode. 

Working Principle :-

Inside the clamp head of the earth tester, there are actually two cores. One core induces a test current and the other measures how much was induced. The input or primary voltage of the test current inducing core is kept constant, so the current actually induced into the test circuit is directly proportional to the loop resistance. This earth tester effectively makes loop resistance measurements. Stake-less measurements are loop measurements. There must be a series-parallel resistance path, and the lower the better. The more electrodes or earth paths in the system the nearer the measurement gets to the actual electrode under test true earth resistance. If there isn’t a loop to measure you could create one with a temporary jumper lead.

 

 

 

LIGHTING : - RECOMMENDED ILLUMINANCE LEVELS (COMMERCIAL BLDGS, DRG OFFICES, HOSPITALS, HOTELS, TRANSPORTS, RAILWAYS)

Commercial buildings
Offices
General Offices	300
Deep Plan General Offices	500
Computer Works Station	300
Conference Rooms, Executive Offices	300
Computer and Data Preparation Rooms	300
Filing Rooms	200
Drawing Offices
General	300
Drawing Boards	500
Print Rooms	200
Counter, Office Area	300
Public Area	200
Retailing
Small Shops with counters	300
Small Self Service Shops with Island Displays	300
Super Markets – Hyper-Markets	300
General	300
Checkout	300
Showrooms for large objects, for example, cars, furniture	300
Shopping precincts and arcades	100
Hospitals
Anesthetic Rooms
General	200
Local	750
Consulting Area
General	200
Examination	750
Corridors
General	100
Ward Corridors
Day, Screened from Bays	150
Day, open to nature light	150
Cubicles
General	200
Treatment	750
Examinations
General	200
Local Inspection	750
Intensive Therapy
Bed Head	30
Circulation Between Bed ends	50
Observation	200
Local Observation	750
Staff base (day)	200
Staff base (Night)	30
Laboratories
General	200
Examination	300
Nurses ‘s stations
Morning/Day/evening	200
Night desks	30
Night, Medical Trolleys	50
Operating Theatres
General	300
Local	10000
Hotels
Entrance Halls	50
Receptions, Cashiers & Porter’s desks	200
Bars, Coffee base, dining rooms, Grill rooms, Restaurants, Lounges
Cloak Rooms, Baggage Rooms	50
Bed Room	30
Bath Rooms	50
Food Preparation & Stores, cellars, Lifts and corridors	100
Transport
Air ports	150
Ticket Counters, Checking, desks and information desks	300
Departure Lounges, other waiting Areas	150
Baggage reclaims	150
Baggage Handling	50
Customers & Immigration halls	300
Concourse	150
Railway Stations
Ticket Office	300
Information Office	300
General	50
Counter	150
Waiting Rooms	150
Concourse	150
Time Table	150
Ticket Barriers	150
Platforms (Covered)	30
Platforms (Open)	20

LIGHTING : - RECOMMENDED ILLUMINANCE LEVELS (MACHINE SHOP, MOTOR VEHICLE PLANTS, PAPER WORKS, PHARMACEUTICALS, TEXTILE, SHEET METAL ,STORES)

XIV) MACHINE AND FITTING SHOPS
a) Rough bench and machine work	150
b) Medium bench and machine work,	300
ordinary automatic machines, rough
grinding, medium buffing and polishing
c) Fine bench and machine work, fine automatic machines,	700
medium grinding, fine buffing and polishing
XV) MOTOR VEHICLE PLANTS
a) General sub-assemblies, chassis assembly and car assembly	300
b) Final inspection	450
c) Trim shops, body sub-assemblies and body assembly	300
d) Spray booths	450
Paint Works
a) General, automatic processes	200
b) Special batch mixing	450
c) Colour matching	700
Paint Shops and Spraying Booths
a) Dipping, firing and rough spraying	150
b) Rubbing, ordinary painting, spraying and finishing	300
c) Fine painting, spraying and finishing	450
d) Retouching and matching	700
XVI) PAPER WORKS
a) Paper and board making :
1) Machine houses, calendering, pulp mills, preparation	200
plants, cutting, finishing and trimming
2) Inspection and sorting (over hauling)	300
b) Paper converting processes :
1) Corrugated board, cartons, containers and paper	200
sack manufacturer, coating and laminated processes
2) Associated printing	300
XVII) PHARMACEUTICALS AND FINE CHEMICAL WORKS
a) Raw material storage	200
b) Control laboratories and testing	300
c) Pharmaceuticals manfuacturing :
1) Grinding, granulating, mixing and drying, tableting,	300
sterilizing and washing, preparation of solutions and
filling, labelling, capping, cartoning and wrapping and
inspection
d) Fine chemical manufacture :
1) Plant processing	200
2) Fine chemical finishing	300
XVIII) PLASTIC WORKS
a) Manufacture (see Chemical Works)
b) Processing:
1) Calendaring and extrusion	300
2) Moulding- compression and injection	200
3) Sheet fabrication:
i) Shaping	200
ii) Trimming, machining, polishing	300
iii) Cementing	200
XIX) ELECTROPLATING SHOPS
a) Vat and baths, buffing, polishing and burnishing	150
b) Final buffing and polishing	Special lighting
Pottery and Clay Products
a) Grinding, filter pressing, kiln rooms, moulding, pressing,	150
cleaning, trimming, glazing and firing
b) Enamelling, colouring, decorating	450
XX) SHEET METAL WORKS
a) Bench work, scribing, pressing, punching,	200
shearing, stamping, spinning and folding
b) Sheet inspection	Special lighting
XXI) TEXTILE MILLS (COTTON OR LINEN)
a) Bale breaking, blowing, carding, roving, slubbing, spinning	150
(ordinary counts), winding, heckling, spreading and cabling
b) Warping, slashing, dressing and dyeing, doubling	200
(fancy) and spinning (fine counts)
c) Healding (drawing-in)	700
d) weaving :
1) Patterned cloths and fine counts, dark	700
2) Patterned cloths and fine counts, light	300
3) Plain grey cloth	200
e) Cloth inspection	700
XXII) TEXTILE MILLS (SILK OR SYNTHETICS)
a) Soaking, fugitive tinting, conditioning or setting	200
or twist.
b) Spinning	450
c) Winding, twisting, rewinding and coining, quilting and
slashing :
1) Light thread	200
2) Dark thread	300
d) Warping	300
e) Healding (drawing-in)	700
f) Weaving	700
g) Inspection	1000
XXIII) TEXTILE MILLS (WOOLEN)
a) Scouring, carbonizing, teasing, preparing, raising,	150
brushing, pressing, back-washing, gilling, crabbing
and blowing
b) Blending, carding, combing (white), tentering, drying	200
and cropping
c) Spinning, roving, winding, warping, combing (coloured)	450
twisting
d) Healding (drawing-in)	700
e) Weaving :
1) Fine worsted	700
2) Medium worsteds and fine woollens	450
3) Heavy woollens	300
f) Burling and mending	700
g) Perching :
1) Grey	700
2) Final	2000
XXIV) WAREHOUSES AND BULK STORES
a) Large material loading bays	100
b) Small material racks	150
c) Packing and dispatch	150