Explanation of Article 430 on engines, kinetic circuits and control units
Article 430 covers installation requirements for motors, motor circuits, control units, protection of excess pregnancy, protection of the short circuit and separation means.
Installing the engines is complicated because it draws a high current when starting, and often 6 x its full current (FLC). This requires special protection rules and change their size behind those of typical electrical equipment. Below is an overview of the main points of this article, along with cables used for engines and car equipment:
Classification of Mosul
The connections for one engine must have the ≥125 % of FLC engine (for all NEC 430.147-430.150).
For multiple engines, connectors should be all FLCS in addition to 25 % of the higher -rated engine.
Protection of excess pregnancy
The purpose of protecting excess pregnancy is to protect the engines and sub -circuit connectors from the prolonged current that causes high temperature, not from short circuits or ground errors.
The protection of excess pregnancy for most engines is required, except for cases where greater risks can be provided (for example, fire pumps).
Triple settings to protect excess pregnancy are:
Common excess pregnancy devices:
Thermal pregnancy phase
Integrated thermal protectors
Included temperature detectors (for engines exceeding 1500 hp)
Double or eclipse valves are correctly classified (if allowed)
Protect the short circle and ground error
Protecting the short circle and the ground error protects the engines, controlled units, and connectors from sudden errors that can cause slope, equipment or fire damage.
It should be separate from the protection of excess pregnancy.
Devices should allow a high motor current when starting without stumbling.
Below is an example of scaling – the FLC 20A engine may require the timeline delay that was rated by 175 % to 250 % of FLC, depending on the type and duty.
Includes protection methods:
Control units
Separation of the means
All unscrupulous conductors must be separated and in the view of the console (i.e. 50 feet and visual)
You must have ampacity ≥115 % of FLC for the engine
Acceptable connection types vary depending on the size of the engine (for example, circuit breaker, engine key, connection/bowl)
Control circuits
It should be protected from excess and mechanical damage
The connection should be cut when the engine joint is opened
Earth errors should not start the cross engine
Cables used in car circuits and car equipment
Energy feeding for engines
Thhn / thwn-2
It is used for the engine branch circles and the nutritional circuits in the channel
600V Thwn-2 Certified Certificate for Wet sites
Common in air conditioning, pumping and equipment in industrial environments
Xhhw / xhw-2
600V, 90 ° C/dry (xhw-2)
For engines in the humid or outdoor channel
Not for direct burial
Rhh / rhw / rhw-2 / USE-2
600 volts, 90 ° C Classical Classification (RHW-2, use 2)
RHW-2: A wet/dry channel, above or below the ground
USE-2: Direct burial only, not for internal use
Used for the long operation of the external engines (for example, pumps)
MC Cable (Clad Metal)
It is used for the engine branch circles and nutritional circuits in dry internal sites without a channel
Suitable for open or hidden operation in equipment rooms, mechanical spaces, and above the ceilings
Available with PVC or XLPE insulation; 600 volts classification
It was not approved for direct burial or wet sites unless a sign is specifically marked
Stair cable (TC-AR)
Used in cable trays or for open operation from control panels to engines
Suitable for industrial environments with a limited channel
It can include monitoring connectors and are protected
VFD cable
Designed specifically for engines controlled by variable frequency engines
The shielding to reduce EMI/RFI and the insulation classified for high voltage
It prevents tolerance of overlap and reference entering
Saoo / Siu, a flexible wire
It is used for mobile motor applications or equipment that requires flexibility
Oil, water and sunlight resistance
Common
Internal wires in engines and equipment
P lead wire
High temperatures, corrosion resistant, and compressed
The size is based on the engines of the engine and usually ended within the terminal cans
MTW (machine tool wire)
Uses inside beginners in cars, control units, and industrial machines
Flexible, oil resistant, flame interview; It was classified for 600 volts
It is common in control attachments and machine wires
Connect (for example, AWM, TEW)
Used in internal wires in engines, paintings and terminal boxes
Usually used for the internal circuits of light service (not for energy food)
AWM (the material of the hardware wire) varies widely in isolation and classification based on the type
