No, each conduit must contain a separate grounding conductor.
The conductors of any three phase circuit must be run in the same conduit. If the circuit requires a neutral, it must also run with the conductors in the same conduit. (If they were to be run in more than one conduit or raceway, the circuit would not operate properly.)
Yes they can. If the feeders are of different sizes, then a conduit fill calculation must be made to ascertain that the conduit does not become overfilled. Cross sectional areas of the conductors are found and it is then determined what the conduit cross sectional fill will allow.
To make sure that a feeder cable is secure it must be supported. The support distance is stated in the electrical code book. The code also gives support of cable trays, conduit and all the different ways to support cables.
Except for the ground wire they must be insulated.
The 2008 NEC code states that conduit must be strapped within 36" or 3 feet from every box or connector, then every 5 feet is acceptable from there.
A service head or LB fitting must be attached to the top end of a conduit riser where conduit is used in a service. This provides a termination point for the conduit and allows for easy access to the conductors inside the conduit.
No, each conduit must contain a separate grounding conductor.
When exist a junction box EMT, conduit must be supported within 18 inches.
The conductors of any three phase circuit must be run in the same conduit. If the circuit requires a neutral, it must also run with the conductors in the same conduit. (If they were to be run in more than one conduit or raceway, the circuit would not operate properly.)
Yes they can. If the feeders are of different sizes, then a conduit fill calculation must be made to ascertain that the conduit does not become overfilled. Cross sectional areas of the conductors are found and it is then determined what the conduit cross sectional fill will allow.
No test is needed. The conduit sizes are laid out in the electrical code book. It states the current carrying capacity of each of the conduit sizes. These test were done by an underwriters test laboratory and approved to carry the stated current capacities. Where the trouble might arise is with the workmanship of the installation. An example, when threads in electrical conduit are involved wrenches must be used not just hand tight, The same thing goes with lock rings, hammer them on not just finger tight. The metallic conduit system needs to be tight to work. There are new code changes coming down the line that will state that a ground wire will have to be pulled along with the feeder wires in a metallic conduit system.
To make sure that a feeder cable is secure it must be supported. The support distance is stated in the electrical code book. The code also gives support of cable trays, conduit and all the different ways to support cables.
The Philippine Electrical Code (PEC) specifies that a conduit run should not have more than two bends between pull points, such as junction boxes or fittings. This limit is established to ensure that wires can be pulled through the conduit without excessive difficulty or risk of damage. If more bends are necessary, additional pull points must be installed to facilitate the installation of the conductors. Always refer to the latest version of the PEC for detailed requirements.
The National Electrical Code (NEC) requires that rigid conduit be strapped or supported at specific intervals to ensure safety and stability. Generally, rigid conduit must be secured within 10 feet of the last coupling or fitting and at least every 10 feet thereafter. Additionally, it should be supported within 3 feet of any outlet box, junction box, or other fittings. Always refer to the latest version of the NEC or local codes for specific requirements.
You can have only one current carrying conductor in a conduit, but that conduit must have a slot to relieve the eddy currents that will be created by the transformer effect created by the conductor. It is better to run the neutral or opposite conductor along with the hot conductor together in the same conduit, or through the same penetration, so as to minimize this effect.
Except for the ground wire they must be insulated.