This is what Copilot says:

The key difference between 400Hz and 60Hz generators lies in their frequency and applications:

• 60Hz Generators: These are the standard for most residential, commercial, and industrial power systems. They operate at a lower frequency, making them suitable for general electrical equipment, motors, and appliances.
• 400Hz Generators: These are primarily used in aviation, military, and specialized industrial applications. The higher frequency allows for lighter and more compact electrical components, which is crucial for aircraft and military equipment.

Technical Differences:

• Size & Weight: 400Hz generators are smaller and lighter compared to 60Hz generators of the same power rating.
• Efficiency: Higher frequency reduces the size of transformers and electrical components, making 400Hz systems more efficient in weight-sensitive applications.
• Compatibility: Most standard electrical devices are designed for 60Hz, meaning 400Hz power requires specialized equipment or conversion2.

Would you like to explore how to convert between these frequencies?

 

You've been really great at giving unhelpful, condescending bits of advice. Do you expect a driving instructor to know the history and inner workings of an internal combustion engine before telling his class not to put diesel in a gas car? I can't give you the full details of why, but my students will typically have access to a 400 Hz generator that is bolted on to one system, and an additional system that has the same voltage requirements but does not always have the 60 Hz generator required to run it. Some one who does NOT KNOW why my students can't use the generator they already have will ask them to use it to run the 60 Hz equipment. I want my students to be prepared to quickly explain why it is not possible, and understand that they will need to request a 60 Hz generator instead.

I don't like incompetency in teachers as it can get people hurt or killed on the job. So yes, I am being unhelpful, condescending because I care about the students. If you want to do something you're not qualified (per your own words) to do in a teaching setting IMO, that's on you.

You can't really teach your students what they need and asking us for a short info sheet is not going to fix that.

Give them a 400Hz and 60Hz info card from what's posted here and don't try to fake it.

 

I don't like incompetency in teachers as it can get people hurt or killed on the job. So yes, I am being unhelpful, condescending because I care about the students. If you want to do something you're not qualified (per your own words) to do in a teaching setting IMO, that's on you.

You can't really teach your students what they need and asking us for a short info sheet is not going to fix that.

Give them a 400Hz and 60Hz info card and don't try to fake it.

You're being unhelpful because you care about the students? Opinion disregarded.

 

You're being unhelpful because you care about the students? Opinion disregarded.

Yes, that's fine, worth what you paid for it. It's just another devils advocate position to pull the true facts out of the matter.

I've been a student all my live and a teacher at times too. So, yes care about the students more that I care about the teacher unless that teacher is exceptional.

 

Why does anyone need an analogy for Hertz? How is it different from needing an analogy for seconds?

 

I have taught at a major university for over 50 years and have encountered instructors who either have poor knowledge of what they were teaching or no true desire to teach it, sometimes both, sadly.

Do your students a favor and teach what you truly know.

 

You've been really great at giving unhelpful, condescending bits of advice. Do you expect a driving instructor to know the history and inner workings of an internal combustion engine before telling his class not to put diesel in a gas car?

No, but I do expect him not to tell the students that diesel will poison the 200 little horses inside the engine.

 

Yes, that's fine, worth what you paid for it. It's just another devils advocate position to pull the true facts out of the matter.

I've been a student all my live and a teacher at times too. So, yes care about the students more that I care about the teacher unless that teacher is exceptional.

The true facts of the matter are I'm qualified to teach how to turn something on and hook it up, not why it matters.

I have taught at a major university for over 50 years and have encountered instructors who either have poor knowledge of what they were teaching or no true desire to teach it, sometimes both, sadly.

Do your students a favor and teach what you truly know.

Yep, I'm just gonna stay on the topic of how to turn the stuff on. If they ask me why they can't use a 400 Hz generator for certain applications, ill tell them it's not rated for 400 Hz and that they need to go get a degree if they want to know more. Obviously there is too much to it for a brief explanation.

 

The true facts of the matter are I'm qualified to teach how to turn something on and hook it up, not why it matters.

Yep, I'm just gonna stay on the topic of how to turn the stuff on. If they ask me why they can't use a 400 Hz generator for certain applications, ill tell them it's not rated for 400 Hz and that they need to go get a degree if they want to know more. Obviously there is too much to it for a brief explanation.

The simple answer is, 400 Hz is used in avionics because it makes all electrical equipment have less weight.

 

The simple answer is, 400 Hz is used in avionics because it makes all electrical equipment have less weight.

Thank you. Can you explain why it would be necessary for ground equipment to require 400 Hz too, besides making the equipment lighter?

 

Thank you. Can you explain why it would be necessary for ground equipment to require 400 Hz too, besides making the equipment lighter?

It is most likely to be equipment that was originally intended for use on aircraft.

 

It is most likely to be equipment that was originally intended for use on aircraft.

I can tell you the housing of our 60 Hz gens are exactly the same size as our 400 Hz ones, and the weight difference is only 20 lbs. The 400 Hz generator is powering a radar, do radars need higher frequency to operate? I'm asking for my own knowledge now, this stuff is not taught for my job.

 

I can tell you the housing of our 60 Hz gens are exactly the same size as our 400 Hz ones, and the weight difference is only 20 lbs. The 400 Hz generator is powering a radar, do radars need higher frequency to operate? I'm asking for my own knowledge now, this stuff is not taught for my job.

Normally a 60Hz generator would be powered by a diesel engine running at 1800 rpm. What powers your 400Hz generator? It certainly won't be a diesel engine running at 12000 rpm! Is it a diesel engine with a multi-pole alternator? In which case the engine won't be much lighter than the one in the 60Hz generator.
An alternator in an aircraft would much more likely to be able to connect to a higher speed shaft.
The need for 400Hz for a radar might be something to do with the speed it rotates, and what type of motor is used to rotate it, especially if it dates from the days before variable speed drives. Or it could have originated for in-aircraft use.

 

Normally a 60Hz generator would be powered by a diesel engine running at 1800 rpm. What powers your 400Hz generator? It certainly won't be a diesel engine running at 12000 rpm! Is it a diesel engine with a multi-pole alternator? In which case the engine won't be much lighter than the one in the 60Hz generator.
An alternator in an aircraft would much more likely to be able to connect to a higher speed shaft.
The need for 400Hz for a radar might be something to do with the speed it rotates, and what type of motor is used to rotate it, especially if it dates from the days before variable speed drives. Or it could have originated for in-aircraft use.

It's operating speed is 900 rpm, and it has a 4 pole generator. Maybe it was used to start aircraft back in the day? If so, I still don't understand why we are using it for a radar now, and why it is paired with every one that we have.

 

It's operating speed is 900 rpm, and it has a 4 pole generator. Maybe it was used to start aircraft back in the day? If so, I still don't understand why we are using it for a radar now, and why it is paired with every one that we have.

A 4-pole generator would have to run at 12000 rpm to generate 400Hz. Presumbly, if the engine runs at 900 rpm (slow, unless it is a really big diesel) then there must be a gearbox to speed up the drive to the alternator.

 

A 4-pole generator would have to run at 12000 rpm to generate 400Hz. Presumbly, if the engine runs at 900 rpm (slow, unless it is a really big diesel) then there must be a gearbox to speed up the drive to the alternator.

Or it generates the 400Hz via an inverter.

 

Or it generates the 400Hz via an inverter.

If so, they could attach the inverter to the output of the other generator!
My suspicion is that we are dealing with old technology here. In which case, a frequency changer would consist of an induction motor driving an alternator through a gearbox!

 

The reason 400 cycles is used anywhere is because it allows all magnetic devices to be lighter and smaller. THAT IS THE REASON!! IT IS STRICTLY for weight reduction.
THAT is a totally honest and totally correct explanation!! And in aircraft, lighter is better.

 

The reason 400 cycles is used anywhere is because it allows all magnetic devices to be lighter and smaller. THAT IS THE REASON!! IT IS STRICTLY for weight reduction.
THAT is a totally honest and totally correct explanation!! And in aircraft, lighter is better.

Thank you. Since the generator is mounted on a truck and is essentially the same weight as the 60 Hz, I have no idea why they went with the 400 Hz. I'll just be letting my students know not to mix them up.

 

Always read the Specification-Plate,
400Hz and 50/60Hz are not compatible with each other,
and will cause damage to Equipment if exchanged with each other,
regardless of "they look the same" or "they weigh the same".

For equal weight, and/or, equal size,
the 400Hz-Generator is capable of supplying more Power.

400Hz and 50/60Hz Generators also operate at substantially different standardized Voltages.

As far as I know, ( which might not be very far in this case ).

400Hz Generators are usually 3-Phase,
Single-Phase would be a very unusual application,
400Hz Generators are exclusively for specialized Military applications.

50/60Hz Generators may be Single-Phase or 3-Phase,
or even both at the same time,
depending upon the requirements of the intended application.
.
.
.