Download EET 276 Chapter 13 Homework: PLC Installation and

EET 276 Chapter 13 Homework: PLC Installation and Troubleshooting
1) What NEMA number cabinet is recommended to be used with PLC Installations?
a) This style of cabinet is made of what?
b) What will this kind of material minimize?
2) The temperature in a cabinet must not exceed what level?
3) Why should a PLC be mounted horizontally?
4) Power to what part of the PLC is not controlled by the MCR?
5) Why can a standard control PLC not be used to control safety circuits?
a) What should be used to monitor the safety circuit?
6) Power coming into a PLC Cabinet will first go through what 2-section device?
7) What 2 functions will a transformer perform for PLC supply voltage?
8) What 2 forms of noise can interfere with a PLC?
a) Arch-welding that causes voltage dips, and raises the ground voltage, would be what kind of noise?
b) Voltage surges in the wires that connect VFDs to the motor they drive would be an example of what
kind of noise?
9) What is an SMP?
a) SMPs cause what kind of distortion in a Power system?
b) What can this distortion do to power transformers that supply the system?
10) What 4 things done by the PLC manufacturer and the Installer can reduce electrical noise?
11) What is STP cable?
12) What kind of cable is best at ignoring radiated electrical noise?
a) What is the effect of twisting the wires?
b) What is the effect of the shield?
c) What type of amplifier in the PLC Analog input helps the PLC to ignore the same noise on both
wires?
d) What is a “Bleeder wire”?
e) What can the result be of grounding the wire around the Shield at both the sensor and the PLC if the
sensor is connected to a different ground than the PLC?
f) What are the 4 guidelines of running analog wire?
13) Noise suppression devices should be installed around what kinds of electrical loads.
a) What device will suppress inductive kick in DC systems?
b) The device above should be “pointed” which way?
c) What device will suppress inductive kick in AC systems?
14) What can be done to eliminate false positives from 2 wire
proxes? What is connected from where to where?
15) What can be done to drain the “Off-State Output current from
DC electronic outputs? What is connected from where to where?
16) All grounds should be connected to what “naked metal” block?
a) How should this “nude block” be attached to the cabinet? Mention paint and kind of screws.
17) How should the PLC be grounded to the Panel? Mention any required wires, screws and how the
screws are used.
18) You wish to use one tablet to program PLCs from 3 manufacturers. What will you need?
19) How can you check the connections without over-tightening?
20) How should dust be removed from inside the cabinet?
21) If filters are used in the cabinet to filter dust what must be done with them?
22) What will happen to the program of a PLC if the battery dies and the power to the PLC is cycled off?
a) How can you tell if the PLC battery is dead?
23) Describe a networked method to archive the most current program in a PLC.
24) Describe a low-cost archiving method for PLC program archiving using USB drives.
25) What is the most common failure in a PLC system?
26) If an input is forced on will it change the way the program executes?
27) If and output is forced will it change the way the program executes?
28) How can you tell if a force has been applied in a PLC?
29) Explain how a TND can be used to localize a fault playing “halfsies”?
30) What command will cause the PLC to stop operation and “Freeze” the Data tables if a set of
conditions exist?
a) Where is the “Freeze-Code” stored?
31) When troubleshooting each measurement, or part replacement, should do what to the number of
possible sources of the problem?
32) What Rockwell program communicates between all Rockwell software and Allen Bradley devices
from the file servers to an intelligent hot-tub thermostat?
33) What Rockwell program is used to monitor and modify PLC programs in smaller, stand-alone
systems?
34) What Rockwell program is used to monitor and modify PLC programs in larger, networked systems?
35) Most smaller PLC systems use what serial protocol to connect a computer to a PLC?