instructor guide - transit training

Instructor Guide

300: Input Output Control EquipmentModule 2: Elevator Input/Output Control Equipment

Elevator-Escalator – Elevator Input/Output Control Equipment

Instructor’s Guide

Table of Contents

1

Overview……………………………………………………………………………………………..…..……....4 Sensors………………………………………………………………………………………………………….17 Switches………………………………………………………………………………………………………...33 Indicators……………………………………………………………………………………………………….49 Summary………………………………………………………………………………………………………..53


Instructor’s Guide Icons Used In This Guide Agenda

Topic # Topic Title Duration

Total Time:

2

1

2

3

4

5

Overview

Sensors

Switches

Indicators

40 Minutes

40 Minutes

40 Minutes

40 Minutes

120 Minutes

300 Minutes

Summary

Field Trip

30 Minutes 6



Overview Purpose The purpose of this module is to:

Objectives At the end of this lesson, the transit elevator/escalator trainee will be able to:

Materials Mandatory Make sure you have the following

Optional You may also want the following for optional activities:

3

Provide the participant with an in depth look at how input and output control devices in transit elevators work by using a schematic from a common elevator.

• PowerPoint Presentation • Coursebook • Quizzes • Pencils

• Chalk board with chalk, large paper with marker, etc.

• Internet connection • Lab, simulator or out of service elevator

• Identify and describe the function of variable control devices in an elevator system

• Identify and describe the function of sensors in an elevator system

• Identify and describe the function of switches in an elevator system

• Identify and describe the function of indicators in an elevator system


DO SAY Materials Needed


In your own words:

Instructor’s Notes

4

Module Length: 300 min Time remaining: 300 min This section: 40 min (12 slides) Section start time: ________ Section End Time: ________

Welcome to the course on Elevator Input/Output Control Equipment. The purpose of this module is to provide the participant with an in depth look at how input and output control devices in transit elevators work by using a schematic from a common elevator. Advance

PPT slide 1 REVIEW introduction slides




In your own words:


5


Elevators are part of the transit vertical transportation system. Their purpose, to take passengers to a different level of a building via an elevator car that either ascends or descends. Advance You may recall from earlier courses this illustration. Click on the movie camera. ASK: What is happening here? Allow participants to briefly discuss the animated illustration. Today, we want to take a closer look at the control equipment responsible for an elevator’s effective operation. Advance

PPT slide 2 REVIEW slide

Internet connection

Multimedia

ASK




In your own words:


6


Today we will • Identify and describe the function of

variable control devices in an elevator system

• Identify and describe the function of sensors in an elevator system

• Identify and describe the function of switches in an elevator system

• Identify and describe the function of indicators in an elevator system

Advance

PPT slide 3 REVIEW module objectives




In your own words:


7


Lets take a look at some of the key words we will be defining as move through this module: • Door timer • Field wire • Fire service indicator light • Governor switch • Latency timer • Non-variable control devices Advance • "Safety on" light • Phase reversal • Reverse phase sensor • Supply voltage • Variable control devices Advance

PPT slide 4 REVIEW key terms




In your own words:


8

PPT slide 5 Thinking back to other courses or just in general, what do we already know about: • Control devices in elevator systems? • Sensors, switches, indicators? Allow participants to think for a minute and perhaps discuss with a partner ideas as well as write down any ideas. Discuss participant responses and if possible list them on a chalk board or similar. Control devices are devices that communicate with the controller to impact the operation of a given system. In elevators and escalators this includes start up, speed up, slow down, stopping, and directional change Advance


ASK participants

SMALL GROUP ACTIVITY

WRITE

Paper Pencils or pens Larger paper ,

chalk board, or similar




In your own words:


9

PPT slide 6 In this module we will examine how the different input/output control devices of a transit elevator communicate with each other and the system at large. We will focus specifically on how components relate to each other and how this information travels along a specific schematic from an MCE controller for a Traction elevator. Advance In the following pages we will give examples of three different types of input/output devices: Sensors Switches Indicators Advance

REVIEW slides





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10

PPT slide 7 Control Devices can either be non-variable or variable. Non-variable control devices are just like they sound - they are set by the manufacturer to activate at a certain threshold and cannot be adjusted. A few examples of non-variable control devices are below: ASK: What might be some examples of non-variable control devices? Allow participants to share possible answers. Advance for correct answers.

REVIEW slide


ASK




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11

PPT slide 7 Examples of non-variable control devices include: Governor Switch Floor Level Sensor Door Safety Curtain Reverse Phase Sensor Gate Switch Door Lock Limit Switches Advance This module, uses the examples of the reverse phase sensor, governor switch and fire service indicator to illustrate how non-variable control devices operate within transit elevators. Advance

REVIEW slide


ASK




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12

PPT slide 8 Variable control devices can be manually adjusted by elevator/escalator technicians to shut off and turn on at different thresholds. ASK: What might be some examples of variable control devices? Allow participants to share possible answers. Advance for correct answers.

REVIEW slide


ASK




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13

PPT slides 8, 9 Examples of variable control devices include: Door Timer Thermal Probe Feedback Tachometer/Encoder Brake Switch Load Weighing Sensor Advance A good example of an adjustable variable control device is the door timer. Although the timer comes set to certain specifications by the OEM, technicians can change how long it takes for the door to open and close on a specific piece of equipment. This sort of flexibility is useful at stations where there are known to be a lot of handicapped passengers which may take longer to enter and exit an elevator. Advance

REVIEW slides


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14

PPT slide 10 Lets see what we have learned so far: Tom would like to know about the differences between variable and non-variable control devices. What would you tell Tom? Call on participants for answer Advance once given the correct answer Answer: Non-variable control devices are devices with parameters set by the manufacturer and can not be adjusted by technicians. An example would be a governor switch. A variable control device can be manually adjusted at different thresholds and an example would be a door timer. Advance


ASK




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15

PPT slide 11 ______________ are examples of non-variable control devices. (check all that apply)

a. Brake switch b. Floor level sensor c. Door lock d. Limit switches e. Load weighing sensor

Call on participants for answer Advance once given the correct answer Answer: b., c., d. Advance


ASK




In your own words:


16

PPT slide 12 ______________ are examples of variable control devices. (check all that apply)

a. Load weighing sensor b. Door safety curtain c. Door lock d. Door timer e. Thermal probe

Call on participants for answer Advance once given the correct answer Answer: a., d., e. Advance


ASK




In your own words:


17

PPT slide 13 Phase reversal detection is important if a motor running in reverse may damage the driven machinery or injure personnel. One outcome of an inadvertent phase reversal would be the motor shaft turning in the wrong direction based on the expected outcome when operating its controls. For example if the three incoming power lines; L1, L2, L3 are connected to the motor terminals T1, T2 and T3 in numerical sequence (L1-T1, L2-T2, L3-T3) the motor shaft will rotate in a clockwise direction. If the phase is reversed on any two phases of a three-phase motor the direction of rotation will change. Therefore if L1 is connected to T3 on the motor, L2 is connected to T2 and L3 is connected to T1 the resultant effect will be a counterclockwise rotation of the motor shaft. Continued

REVIEW slides





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18

PPT slide 13 This is exactly how the direction of an elevator or escalator powered by an ac motor is accomplished. Advance The control circuit reverses two of the phases through the use of a dual contactor in which one contactor “A” is wired L1-T1, L2-T2, L3-T3 Advance and contactor “B’ is wired L1-T3, L2-T2, L3-T1. If contactor “A” is activated the motor shaft will turn in a clockwise direction, if contactor ”B” is activated the motor shaft will turn in a counter clockwise direction. Advance By changing motor direction an elevator can either ascend or descend and an escalator can operate in the up direction or the down direction. Advance

REVIEW slides





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PPT slides 14, 15 The problem with accidental phase reversal must be avoided to protect the passengers on either of these transportation systems. Phase reversal can occur when maintenance is performed on motor-driven machinery, when modifications are made to the power distribution system, or when power restoration results in a different phase sequence than before the power outage. Advance Another name for reverse phase monitor sensor is reverse phase monitor, and The National Electric Code (NEC) requires phase reversal protection on all equipment transporting people, such as escalators or elevators. Advance

REVIEW slides





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20

PPT slide 16 To illustrate how one particular type of sensor operates we can examine the reverse phase sensor. The role of the reverse phase sensor is to sense when the line sequence of the incoming three-phase power system is affected by an unintended phase reversal. In this case, the control circuit will be shut down as to stop the effected equipment. This could be reflected in the user experience by a passenger pushing the up button at a landing area but actually being sent an elevator that is moving to a lower floor. Advance

REVIEW slide





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21

PPT slide 17 Note that there will not always be an error in the passenger experience during a phase reversal - as there are a total of six combinations of the phase orderings (much like in a boxed number for the daily lottery). Of these six combinations, three will operate the motor clockwise and 3 will run the motor counterclockwise - meaning that there is a 50% chance that the user experience will be correct even if a phase reversal has occurred. Advance

REVIEW slide





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22


Let’s see how this works. Advance REFER participants to their course books for a closer view of the diagram. The 460 VAC Three phase supply line voltage is connected to L1, L2 and L3 in the upper left hand side of the diagram. Advance

PPT slides 18, 19 REVIEW slides

REFER participants

Course book




In your own words:


23


REFER participants to their course books for a closer view of the diagram. The three power lines are connected to the input terminals of the Reverse Phase Sensor (RPS) through fuses FL1, FL2 and FL3. Advance Line 1 is connected to terminal 3, Line 2 is connected to terminal 4 and Line 3 is connected to Terminal 5. Since the three phase inputs of the RPS are wired directly to the incoming lines in the proper sequence, if any two of these lines are reversed prior to entering the terminals for this system the RPS sensing relay will detect the change. Advance


REFER participants

Course book




In your own words:


24


The computer (main controller) generates a signal that emanates from output CSAF (CPU output). Advance If the phasing is correct, the signal continues through SAF1 and then through the normally open RP1 socket and to the base of RP2 socket - completing the circuit. Advance Under normal operation, the relay between RP1 and RP2 is energized. Advance Once the output that was released from CSAF is returned to SAF, the system can operate normally – allowing the power to continue to the main run power circuit on the control side. This allows the drive system to be energized and for the car to move normally. Advance





In your own words:


25


REFER participants to their course books for a closer view of the diagram. Again, here it is on the diagram. The computer (main controller) generates a signal that emanates from output CSAF (CPU output). Advance If the phasing is correct, the signal continues through SAF1 and Advance then through the normally open RP1 socket and to the base of RP2 socket - completing the circuit. Under normal operation, the relay between RP1 and RP2 is energized. Once the output that was released from CSAF is returned to SAF, the system can operate normally – allowing the power to continue to the main run power circuit on the control side. Continued


REFER participant

Course book




In your own words:


26


This allows the drive system to be energized and for the car to move normally. Advance In a case of phase reversal, the relays are de-energized and the power to the main run power circuit is disconnected. Loss of power causes the drive systems to de-energize and for the car to stop moving. Advance REFER participants to their course books for a closer view of the diagram. Note that the relays shown include SAFB, the safety brake. Advance

PPT slides 23, 24, 25 REVIEW slides

REFER participant

Course book




In your own words:


27


The brake on traction elevators is released under normal operation and closes/brakes when power is cut off. Note that there is a latency timer so that the car is electrically stopped before the brake is set. Advance REFER participants to their course books for a closer view of the diagram. Here is the schematic illustrating a normally open brake on a traction elevator - ©MCE Advance


REFER participant

Course book




In your own words:


28


The Controller Communicates An Error In the Safety String The "safety on" light in the controller is lit when the circuit is made under normal operation. Any disruption to the safety string will cause the light to go off. Unfortunately, the this light will not give much more information than letting the participant know that something is wrong in the safety circuit - but not what is wrong. The safety circuit operates much like a string of old Christmas lights - if there is one break, the entire string goes out with no clear indication of the exact problem from the controller. For more information, consult the controller display. Advance





In your own words:


29


Here is a MCE computer panel board layout illustrating "Safety On" light. Advance Further investigation will be necessary as the power shut down could have been initiated at one of several places including the other switches represented on the next schematic: • Final limit switch • Pit switch • Counterweight Safety • Safety Clamp • Emergency Car Switch • Gate Switch Advance Here is a computer panel board layout illustrating "Safety On" Light - ©MCE Advance

PPT slides 29, 30, 31 REVIEW slides




In your own words:


30

PPT slide 32 Lets see what we have learned so far: Ben is confused about the reverse phase sensor. What would you share with Ben to help him understand this sensor? Call on participants for answer Advance once given the correct answer Answer: The control circuit reverses two of the phases through the use of a dual contactor in which one contactor “A” is wired L1-T1, L2-T2, L3- T3 and contactor “B’ is wired L1-T3, L2-T2, L3-T1. If contactor “A” is activated the motor shaft will turn in a clockwise direction, if contactor ”B” is activated the motor shaft will turn in a counter clockwise direction. By changing motor direction an elevator can either ascend or descend and an escalator can operate in the up direction or the down direction. Advance


ASK




In your own words:


31

PPT slide 33 ______________ light in controller is lit when circuit is made under normal operation.

a. Brake b. Governor c. Limit d. Safety

Call on participants for answer Advance once given the correct answer Answer: d. Safety Advance


ASK




In your own words:


32

PPT slide 34 ______________ allows the car to be electrically stopped before brake sets.

a. Latency Timer b. Late Timer c. Late Brake d. Latency Brake e. Car Timer

Call on participants for answer Advance once given the correct answer Answer: a. Latency Timer Advance


ASK




In your own words:


33

PPT slide 35 ASK: What is the governor? Allow participants to share possible answers. The governor is a mechanical speed control mechanism Advance that stops the elevator when an overspeed condition exists. Advance The governor consists of a wire rope driven centrifugal device used to stop and hold the movement of its driving rope, initiating the activation of the car safety device. Some types of governors operates in the same manner if it overspeeds in the up direction. Advance The governor is usually in the machine room but it may also be in the hoistway or on the car itself. Advance

REVIEW slide


ASK




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34


Here is a governor for an electric traction elevator, courtesy of WMATA. Advance

PPT slides 36, 37 REVIEW slide




In your own words:


35


When any switch on the safety string is tripped, three things happen: The controller communicates an error in

the safety string by turning off the "safety on" light

Power is removed from the control circuit, shutting down the drive circuit

The brake is engaged Advance Just like before with the reverse phase sensor… The "safety on" light in the controller is lit when the circuit is made under normal operation. Any disruption to the safety string will cause the light to go off. Continued





In your own words:


36


Unfortunately, the this light will not give much more information than letting the participant know that something is wrong in the safety circuit - but not what is wrong. The safety circuit operates much like a string of old Christmas lights - if there is one break, the entire string goes out with no clear indication of the exact problem from the controller. For more information, consult the controller display. REFER participants to their course books for a closer view of the diagram. Further investigation will be necessary as the power shut down could have been initiated at one of several places including the other switches represented on this schematic: Final limit switch, Pit switch, Counterweight Safety Safety Clamp, Emergency Car Switch Gate Switch. Advance


REFER participant

Course book




In your own words:


37


When the governor switch is tripped and the circuit is broken - this information is inputted into the control terminal (terminal #16). In this case the SAF coil will drop out signifying that there is an error in the safety string in general. In new systems, each safety device is polled separately, providing more specific information on the failure. This is the case in the print in Figure 11 which shows that terminal #16 connects to the PSS (Pit stop switch) coil. Note that each safety switch activates its own coil. When the corresponding coil drops out, it communicates a fault to the controller. Advance





In your own words:


38


REFER participants to their course books for a closer view of the diagram. Lets look at this in context of the pint. Again, when the governor switch is tripped and the circuit is broken - this information is inputted into the control terminal (terminal #16). In this case the SAF coil will drop out signifying that there is an error in the safety string in general. In new systems, each safety device is polled separately, providing more specific information on the failure. This is the case in the print in Figure 11 which shows that terminal #16 connects to the PSS (Pit stop switch) coil. Note that each safety switch activates its own coil. When the corresponding coil drops out, it communicates a fault to the controller. Advance


REFER participant

Course book




In your own words:


39


Adding on…. Power coming off of terminal #20 is broken, the relays are de-energized – cutting off the main run power circuit on the control side. Loss of power causes the drive systems to de-energize and for the car to stop moving. As this string is connected to the emergency safety switch, the car will stop abruptly no matter where it is in the hoistway. Advance REFER participants to their course books for a closer view of the diagram. Lets look at this in the schematic. You can see terminal #20 is broken here. Advance


REFER participant

Course book




In your own words:


40


REFER participants to their course books for a closer view of the diagram. Note that the relays shown here include SAFB, the safety brake. Advance The brake on traction elevators is released under normal operation and closes/brakes when power is cut off. Note that there is a latency timer so that the car is electrically stopped before the brake is set. Advance


REFER participant

Course book




In your own words:


41

PPT slide 46 Lets see what we have learned so far: Jack would like to know how the governor switch operates. What would you explain to Jack? Call on participants for answer Advance once given the correct answer Answer: The governor is a mechanical speed control mechanism that stops the elevator when an overspeed condition exists. The governor consists of a wire rope driven centrifugal device used to stop and hold the movement of its driving rope, initiating the activation of the car safety device. Some types of governors operates in the same manner if it overspeeds in the up direction. Advance


ASK




In your own words:


42

PPT slide 47 Three events that take place when the safety string is tripped include: Call on participants for answer Advance once given the correct answer Answer: 1)The controller communicates an error in the safety string by turning off the "safety on" light 2)Power is removed from the control circuit, shutting down the drive circuit 3)The brake is engaged Advance


ASK




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43

PPT slide 48 Explain what is taking place in blue box. Call on participants for answer Advance once given the correct answer Answer: The brake on traction elevators is released under normal operation and closes/brakes when power is cut off. Advance


ASK




In your own words:


44

PPT slide 49 ASK: What do we know about the fire service indicator light? Allow participants to share possible answers. The fire service indicator light turns on to alert any passengers when the system is put into fire service. Generally passengers will only be on the elevator when the system is in fire service phase 1 - that is when an emergency is signaled to the system either by the heat/smoke detector(s) or by passenger or emergency personnel. At this point, the light inside the car will turn on and the car will return to the recall floor level. Advance

REVIEW slide


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45


REFER participants to their course books for a closer view of the diagram Power comes in from the mainline disconnect….. Advance …..and connects to the fire safety circuit through 2F fuse from the control feed of the transformer. Advance


REFER participant




In your own words:


46


The smoke/fire detectors are in series with each other and their circuits are normally closed. If excessive heat or smoke is detected at any detector along the hoistway then that circuit will open and stop energy from flowing to subsequent circuits. The output from smoke/heat detector sent to input FRS can either be a binary zero (0) or a binary one (1). In this case, the circuit is normally closed. This means that a "1" would signal that the system is under normal operation and a "0" would signal that there is an emergency situation. If excessive heat or smoke is detected at any detector along the hoistway then that circuit will open and stop energy from flowing to subsequent circuits. Continued





In your own words:


47


Note that the binary translation will differ from system to system – always consult your OEM manual for more information. Advance REFER participants to their course books for a closer view of the diagram. Here is a schematic illustration Inputs from the Fire Bypass Key and Smoke/Fire Detector(s). Advance


REFER participant




In your own words:


48


So, a problem is communicated to the PLC. This reading is then sent back to the PLC via board 3 (on next slide). This information is then passed onto the PLC where the system is put into fire service phase 1. Advance REFER participants to their course books for a closer view of the diagram. Here you can see board 3 which connects the Fire Bypass and Detectors to the PLC. Note that FRBYP is represented on this card as Spare 1. Advance


REFER participant




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49


After the input is registered three things happen: 1. The fire service light inside the car

comes on 2. The fire service light comes on the

controller panel comes on 3. The car returns to the recall landing Advance The PLC sends a signal for the relay to drop, energizing the normally open fire service light (FSO). Then, the Fire Service Light (FSO) comes on inside the car. Advance REFER participants to their course books for a closer view of the diagram. Here you can see a schematic illustrating the FSO Relay. Advance


REFER participant




In your own words:


50

PPT slide 58 Lets see what we have learned so far: What is taking place in the blue box? Call on participants for answer Advance once given the correct answer Answer: Board 3 connects the Fire Bypass and Detectors to the PLC. Advance


ASK




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51

PPT slide 59 Three events that take place when the safety string is tripped include: Call on participants for answer Advance once given the correct answer Answer: 1) Fire service light inside car illuminates 2) Fire service light on control illuminates 3) Car returns to recall landing Advance


ASK




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52

PPT slide 60 At instructor’s discretion, take time to visit the field and provide opportunities for participants to observe the following: • Variable control devices in an elevator

system • Functioning of sensors in an elevator

system • Functioning of switches in an elevator

system • Functioning of indicators in an elevator

system Advance

Module Length: 300 min Time remaining: 140 min This section: 120 min Section start time: ________ Section End Time: ________

ASK

CLASSROOM ACTIVITY




In your own words:


53

PPT slides 61, 62 Read slide. For each objective, briefly review what was learned in this module or ask participants to share what they have learned for each learning objective and briefly discuss as a class. Advance Lets take a look at some of the key words we have defined as moved through this module. Read slide. Discuss definitions as a group. Advance Read slide. Discuss definitions as a group. Advance


CLASSROOM ACTIVITY




In your own words:


54

PPT slides 63 Administer quizzes.


CLASSROOM ACTIVITY Quizzes

Pencils

INDIVIDUAL ACTIVITY

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