Mod 7 Essays (Electrical) Flashcards
How would you measure resistance of a circuit?
DMM - tool crib - Calibration date
General Visual check - no damage
Functions check - black lead ‘‘com’’ jack
red lead - ‘V-ohm’’ jack
Probes across each other - ‘‘0’’ ohms
Remove power circuit - pull CB’s and collar
black lead - ‘‘com’’ jack
red lead - ‘‘V-ohm’’ jack
Select ohms and place tesrt probes in series
Remove test probes, remove safety collars and close relevant CB’s
Function test of DMM again before returning to tool crib
How would you measure the current in a circuit?
DMM - Calibration date not expired
General visual inspection - no damage
Ensure leads have shrouded connectors and finger guards
Recessed input jacks
Continuity check
Overload protection function on OHM’s setting
Pull CBs and tag
BREAK CIRCUIT
Probes at each break so current can flow thoruw DMM
Select AC or DC
Black lead ‘‘COM’’ jack
red lead ‘’ 10 amp or 300 mA’’
Measure in pairs and let people know
Close CB’s and take reading
Pull CB’s, disconnect probes
Red first
Re-connect circuit and close CB’s
Continuity check and return DMM to tool crib
Final check of system to ensure operational
How would you carry out a continuity check
Quick go/no go resistance test
Open and closed circuit
DMM from tool crib - calibration date
General visual inspection
Function test - black lead ‘‘COM’’ jack
red lead ‘‘Vohms’’ jack
Beep should be heard
record results
Remove probes, function test before switching off and returning to tool crib
How would you measure voltage
Calibration date
General visual inspection
Shrouded connectors, finger guards and recessed input jacks
Overload protection function on the OHM setting
Functions check - black ‘‘COM’’ red ‘‘VOhm’’ jacks
Ohms setting and shorting should give 0
Check in pairs, people around you know
Remove power from circuit + collar
Collar with danger tages
Black ‘‘Com’’ jack, red ‘‘Vohm’’ jack
Select VAC or VDC as required
Place probes parallel across component
Close CB’s and record result
Pull CB’s, remove probes
Close CB’s and restore circuit original position
Function test + inspection and return to tool crib
How would you check for a grounded wire or a short circuit?
Calibration date - damage - function check
System troubleshooted - no power - CB’s
Wiring diagram from WDM - start at the end of the wire and locate a point at which the wire disconnects
Continue to do this until you have isolated the problem resulting in a short circuit or grounded wire.
plugs disconnected are reconnected
Restore circuit - CB’s
function + damage check + return
Function check of system
How would you perform a splicing operation.
Damage to a wire - fire detection circuit
2 types - solder and crimped type
Crimped > solder (brittle)
Correct tools - calibration date - damage
Remove power - CB’s
Wiring diagram from WDM
Correct gauge tool to strip wire
Next insert the wire into the splice ensuring the core of the wire can be seen through the inspection hole. Insert the wire and splice into the crimping tool and perform the crimp.
Repeat - staggered - outside - not conduit
12 inches - max 2
Waterproof crimp in pressurised areas
Resistance check - crimped correcly
Return - close CB’s - function check of system
How do you perform a waterproof splice?
essay in word doc
How do you perform a non-waterproof splice?
Word doc
