ELECTRICAL TEST Part A - Technical
What are the different colors of wiring used for various electrical circuits?
AC Control circuit 150 volts or less
Voltages over 150 volts
DC Control Circuit 150 volts or less
Wire is not de-energized when disconnect is off
Equipment grounding (non-current carrying)
Grounded Circuit (current carrying)
What is the difference between THHN vs. MTW wire?
What is the purpose of a diode placed in parallel to relay?
What does CRM stand for?
What does PLC stand for?
The color of wiring used for different electrical circuits can vary, and THHN and MTW wires have different applications. A diode placed in parallel to a relay helps suppress voltage spikes. CRM stands for Customer Relationship Management, and PLC stands for Programmable Logic Controller.
The color of the wiring used for the following is as follows:
- AC Control circuit 150 volts or less: Usually blue color wiring is used.
- Voltages over 150 volts: Usually orange color wiring is used.
- DC Control Circuit 150 volts or less: Usually white color wiring is used.
- Wire is not de-energized when disconnect is off: Usually black color wiring is used.
- Equipment grounding (non-current carrying): Usually green color wiring is used.
- Grounded Circuit (current carrying): Usually white color wiring is used.
THHN and MTW are types of electrical wire insulation. THHN stands for Thermoplastic High Heat-Resistant Nylon, while MTW stands for Machine Tool Wire. The main difference between the two is their applications. THHN wire is commonly used in dry or damp locations, while MTW wire is suitable for wet locations and can be used in both exposed and concealed areas.
A diode placed in parallel to a relay is used to suppress back-emf (electromotive force) or voltage spikes that can occur when the relay is de-energized. The diode allows the energy stored in the electromagnetic field of the relay to dissipate safely.
CRM stands for Customer Relationship Management, which is a system or strategy used by businesses to manage and analyze interactions with customers throughout the customer lifecycle, with the goal of improving customer relationships and driving sales.
PLC stands for Programmable Logic Controller, which is a computer-based control system commonly used in industrial automation processes. PLCs are designed to withstand harsh environments and are used to control machinery and automate processes in manufacturing, chemical plants, and other industrial settings.