A contractor wants to raise the car speed from 100fpm to 125fpm, it
currently has a 12" sheave. What sheave is required? ANS✔✔ Diam=12"
12/4=3" 25fpm=3" 100fpm + 25fpm= 12"+3"= 15" sheave
A MOV (Metal Oxide Varistor) burns out. You replace it, but cannot read
voltage or resistance. What should you do? ANS✔✔ Replace it with a larger
MOV
On a Ward-Leonard circuit the break is set, but the motor is trying to slip
through the break. What is the issue? ANS✔✔ Suicide Circuit
You have an old DC motor and are adding an SCR drive, what do you do to
the interpoles? ANS✔✔ Leave the interpoles alone. When adding a SCR drive
to the generator, the series loop is removed, as are the 3 resistors.
Everything else remains the same
A hydro runs up with no load, but will not run with a full load. What is the
issue? ANS✔✔ The relief valve is set too low
Runby for a 1:1 hits the CWT buffer 4" below the top landing. CWT runby
should be set at 18". How much should the ropes be shortened? ANS✔✔ 22"
You need to work on a freight door retiring cam, you LOTO the main line but
there is still power on the cam. What circuit is still hot? ANS✔✔ Door
Operator Disconnect/ Main Line Disconnect
,The contractor requests that the vertical center of a Rack and Pinion hoist be
moved. How do you do this? ANS✔✔ Adjust Tie Downs and Wall Ties
Working pressure on a Hydro is 400psi. What is the maximum relief valve
setting? ANS✔✔ 400psi x 150%= 600psi
What must be installed on a false car before operation? ANS✔✔ Spring
Loaded Safeties.
There is slight arcing between the brush and commutator. What action must
be taken? ANS✔✔ None.
Heavy arcing=Light brush pressure. Heavy bush pressure=mechanical wear
If rigging gear is roped 3:1 and a BEAM CLAMP is used to lift a 6,000lb load.
What is the beam capacity? ANS✔✔ 18,000lbs. Beam capacity is cut in half
with use of clamp, when rigging all blocks, rope, and clamps will be Equal to
the lowest load rating
How much resistance is measured over a normally closed switch? ANS✔✔
1.2ohms. should be zero, but will never be that low
A car traveling in the hoistway always stops at the same spot and blows a
fuse. What causes this? ANS✔✔ Traveling cable has a cut/exposed wire or a
short
How is a class 1 yearly buffer test preformed? ANS✔✔ Car at bottom landing
and on inspection, jump out direction and final limits. With pit clear, run
down to compress buffers, buffers should fully extend within 90 seconds.
, 5yr: Full load Full speed
CWT: Full speed Empty
How many strain supports are required on a 350ft raceway? ANS✔✔ 4. 1
every 100ft
How is stainless steel drilled out? ANS✔✔ Slow speed and constant pressure
What is the required amount of retainer clips for wedge shackles and what is
the spacing? ANS✔✔ Minimum 2 clips. 1st at a maximum 4x the diameter of
the rope
2nd at a maximum 8x the diameter above the 1st clip
A 300ohm resistor burns out, but you don't have another one. How can you
make one? ANS✔✔ 2 600ohm resistors in parallel is 300ohms. Resistance is
half of highest resistor in parallel circuit.
3 225ohm resistors in parallel is 75ohms.
When cutting laminated panels, which direction should the finish side face?
ANS✔✔ Finish side facing the cutting edge of the tool. Blade will burr the
backside
How do you cut a finished floor? ANS✔✔ Cutting blade away from finished
side
A 480vac stepdown 240vac transformer is connected to a 3 phase rectifier,
what is the output voltage? ANS✔✔ 320vac
3 phase full wave = 1.33x output voltage
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