motor diagram symbols

[Alley Cat Bad Dog]

Hi there,
I'm working on a single line diagram and I'm trying to show all the motors on the MCC, but I'm not sure what is the right way to show it. Note I have some motors with direct connection from the feeder and some with a VFD starter ( which i couldn't find a symbol for it) so what would be the right way to do it?
here is a picture to show what i mean: https://ibb.co/chccbD5
Also is the capacitor & the Overload relay are needed in each motor?
thanks!

 

[Jraef]

That’s not a capacitor, that’s the motor starter, indicating that it is an Across-The-Line starter. Yes, it is necessary on the one-line.

Usually a VFD is shown as just a rectangle with the term VFD inside, often with the size rating and added boxes above or below for Line Reactors or Load Reactors (abbreviated LR). If the VFD is 18 pulse, some people often show the autotransformer some just put “18P” in the box.

But really, you can make up your own way of showing it, so long as you provide a legend sheet to explain ALL of the symbology you use.

 

[Alley Cat Bad Dog]

That’s not a capacitor, that’s the motor starter, indicating that it is an Across-The-Line starter. Yes, it is necessary on the one-line.

Usually a VFD is shown as just a rectangle with the term VFD inside, often with the size rating and added boxes above or below for Line Reactors or Load Reactors (abbreviated LR). If the VFD is 18 pulse, some people often show the autotransformer some just put “18P” in the box.

But really, you can make up your own way of showing it, so long as you provide a legend sheet to explain ALL of the symbology you use.

Yes I looked into this symbology, and it's a motor starter, and the number next to it specify the NEMA size: https://www.engineeringtoolbox.com/nema-starters-d_918.html

but what would be the standard motor starter? if it's not VFD,, will it be a FVNR or a soft starter?

thanks for your explanation!

 

[JimInPB]

The thig that looks like a capacitor, is the contacts of one leg of a contactor. Generally, all legs of the contactor are shown. Generally there is a dashed line between them to show that they all move in unison. For a 3 phase motor, there would be 3 in parallel. For a single phase motor or some DC motors, there would normally be two. The interlocked 3/4 circles are the overload relay. Here too, all legs are normally shown, not just one. The circle that represents the motor usually has an M in it. You can have all sorts of notes next to devices specifying different attributes. For a motor, I normally list voltage, phase number or dc, and kw or hp. For the overload, I normally list the trip current or current range, or both. For the contactor, I may list coil voltage.

The electrical version of autocad has all the symbols for a wide variety of devices already drawn for you. You just select them as needed. If you use the mechanical version or the lt version, then you need to draw each symbol yourself and make your own database of component drawings to be copied & deployed as needed.

VFDs vary a lot. Different ones have different connections. Almost all have RST & UVW, but after that, it could be almost anything. I suspect that is why there are no standard symbols for those devices.

NEMA size starters are one option. IEC is another. There are usually larger jumps in size between NEMA starter frame sizes compared to IEC. IEC are usually easier to adjust for trip current variation. It's generally just a dial that you turn on the overload relay, within a given range. NEMA overloads I have worked with needed to have heaters changed to adjust trip current. The correct heaters are not always easily available

 

[JimInPB]

Actually, a correction to my post above. The "capacitor" is most likely the contacts inside the overload relay. The open switch near the bottom is most likely the contactor. Different countries have different standards for how these things are normally shown. I see a lot of variety.