ELEVATOR MECHANIC UPDATED
COMPREHENSIVE EXAM QUESTIONS AND
ANSWERS SURE A+
✔✔Lula: Limited use/Limited Access (Example Wheelchair Lifts)
Max Rise 25'
Max Speed 30 Ft/Min
Max Capacity 1400 Lbs.
Max Platform Area 18 Sq/Ft.
Residential Elevator:
Max Rise 50 '
Max Speed 40 Ft/min
Max Capacity 940 Lbs.
Max Platform Area 19 Sq/Ft
840 Pg 2
Dumbwaiters:
Platform limited to 9 Sq/Ft
Inside height is limited to no more than 4 Feet
Capacity is limited to 500Lbs
No Riders - ✔✔Read Lula and Dumb waiters
545 Pg 1
,✔✔You never get on top and you work only partially in with the main line OFF - ✔✔If
you get on top of Dumbwaiter what must be done?
545 Pg 14
✔✔Notes:(Pi) π is 3.1416 and 231 Cubic inches to the Gallon
Area:
Remember to ÷ 6" ÷ 2 = 3 to get Radius
Area = π∙ r²
Area = 3.1416 x 3 x 3 = 28.27 inches or 3.146 x 9 = 28.27
Volume
Multiple are times height to solve for Volume
V = A∙H
V = 28.27 x 300 (25" feet x 12" = 300)
V = 8481 Cubic Inches
Since we already know there are 231 cubic inches to the gallon
8481 ÷ 231 = 36.71 Gallons - ✔✔PSI Formula and Gallons (Example) How much oil to
move a 6" jack 25'
815 Pg 10
✔✔Relief Valve :
Must be tested Annually
Its is simply Pressure relief (If car strikes obstruction,Overloaded Car,Car hits stop ring)
If set to light Car may not move!
Check Valve:
It is simply a one way valve permitting oil to flow in one direction
Up Valve:
The most complicated valve in system
Controls Up Start and acceleration to high speed, up slow down, up leveling speed, and
up stopping.
Down Valve:
Because the elevator is not running when on the down direction the down valve
depends on system pressure.
Bypass and Relief Valve:
Have been combined into one - ✔✔Valve Operation
815 Pg 16,17
✔✔Simply:
In a Inverting Op Amp (INPUT) is supplied to the Negative
, In a Non Inverting Op Amp (INPUT) is supplied to Positive - ✔✔Amplifiers (Inverting and
Non Inverting)
640 Pg 11
✔✔Minimum is 2 switches 15 lbs. and must stop the lift within 2" - ✔✔In a vertical lift
how many sensors are required (Pan Switches)
845 Pg Unknown
✔✔SCRs are used in DC door motor control and more commonly in Direct Drives
(Replacing DC Generators)
SCR is a three terminal device. It basically acts as an on/off switch by pulsing the gate
of the SCR with a positive voltage.
Once an SCR is turned on it remains on, till anode and cathode voltages equalize or the
anode and cathode are reversed biased or voltage is removed from the anode and
cathode. - ✔✔SCR's
635 Pg12
✔✔A Meter with the positive lead on the Anode and the negative lead on the Cathode.
A jumper is placed across the Anode and Gate as well
This should show .7 Volts an indication of a Good SCR - ✔✔SCR Example:
635 Pg 14 Figure 26
✔✔In this figure 11 (Pg 7 Unit 625) it shows R¹ which controls the rate that the magnetic
field builds.
R¹ controls the time it takes for the brake to energize after BR contact closes.
R² is in the discharge path of the brake coil. It controls the time it takes for the brake to
set after the BR contact opens.
R² also controls voltage spikes from the collapsing magnetic lines of the brake coil when
discharging. Thus reducing spikes from reaching other parts of the circuit. -
✔✔Inductance In A DC Brake Circuit
625 Pg 7 Figure 11
✔✔Off Delay Timing Circuit:
A typical door timing circuit is shown Figure 30
By installing the diode across the discharge resistor(RD) The capacitor will charge
fast.This ensures full door timing should the closing cycle be interrupted. When the
COMPREHENSIVE EXAM QUESTIONS AND
ANSWERS SURE A+
✔✔Lula: Limited use/Limited Access (Example Wheelchair Lifts)
Max Rise 25'
Max Speed 30 Ft/Min
Max Capacity 1400 Lbs.
Max Platform Area 18 Sq/Ft.
Residential Elevator:
Max Rise 50 '
Max Speed 40 Ft/min
Max Capacity 940 Lbs.
Max Platform Area 19 Sq/Ft
840 Pg 2
Dumbwaiters:
Platform limited to 9 Sq/Ft
Inside height is limited to no more than 4 Feet
Capacity is limited to 500Lbs
No Riders - ✔✔Read Lula and Dumb waiters
545 Pg 1
,✔✔You never get on top and you work only partially in with the main line OFF - ✔✔If
you get on top of Dumbwaiter what must be done?
545 Pg 14
✔✔Notes:(Pi) π is 3.1416 and 231 Cubic inches to the Gallon
Area:
Remember to ÷ 6" ÷ 2 = 3 to get Radius
Area = π∙ r²
Area = 3.1416 x 3 x 3 = 28.27 inches or 3.146 x 9 = 28.27
Volume
Multiple are times height to solve for Volume
V = A∙H
V = 28.27 x 300 (25" feet x 12" = 300)
V = 8481 Cubic Inches
Since we already know there are 231 cubic inches to the gallon
8481 ÷ 231 = 36.71 Gallons - ✔✔PSI Formula and Gallons (Example) How much oil to
move a 6" jack 25'
815 Pg 10
✔✔Relief Valve :
Must be tested Annually
Its is simply Pressure relief (If car strikes obstruction,Overloaded Car,Car hits stop ring)
If set to light Car may not move!
Check Valve:
It is simply a one way valve permitting oil to flow in one direction
Up Valve:
The most complicated valve in system
Controls Up Start and acceleration to high speed, up slow down, up leveling speed, and
up stopping.
Down Valve:
Because the elevator is not running when on the down direction the down valve
depends on system pressure.
Bypass and Relief Valve:
Have been combined into one - ✔✔Valve Operation
815 Pg 16,17
✔✔Simply:
In a Inverting Op Amp (INPUT) is supplied to the Negative
, In a Non Inverting Op Amp (INPUT) is supplied to Positive - ✔✔Amplifiers (Inverting and
Non Inverting)
640 Pg 11
✔✔Minimum is 2 switches 15 lbs. and must stop the lift within 2" - ✔✔In a vertical lift
how many sensors are required (Pan Switches)
845 Pg Unknown
✔✔SCRs are used in DC door motor control and more commonly in Direct Drives
(Replacing DC Generators)
SCR is a three terminal device. It basically acts as an on/off switch by pulsing the gate
of the SCR with a positive voltage.
Once an SCR is turned on it remains on, till anode and cathode voltages equalize or the
anode and cathode are reversed biased or voltage is removed from the anode and
cathode. - ✔✔SCR's
635 Pg12
✔✔A Meter with the positive lead on the Anode and the negative lead on the Cathode.
A jumper is placed across the Anode and Gate as well
This should show .7 Volts an indication of a Good SCR - ✔✔SCR Example:
635 Pg 14 Figure 26
✔✔In this figure 11 (Pg 7 Unit 625) it shows R¹ which controls the rate that the magnetic
field builds.
R¹ controls the time it takes for the brake to energize after BR contact closes.
R² is in the discharge path of the brake coil. It controls the time it takes for the brake to
set after the BR contact opens.
R² also controls voltage spikes from the collapsing magnetic lines of the brake coil when
discharging. Thus reducing spikes from reaching other parts of the circuit. -
✔✔Inductance In A DC Brake Circuit
625 Pg 7 Figure 11
✔✔Off Delay Timing Circuit:
A typical door timing circuit is shown Figure 30
By installing the diode across the discharge resistor(RD) The capacitor will charge
fast.This ensures full door timing should the closing cycle be interrupted. When the
