Rated Load: Definition & Relationship to Voltage & Current

  • Thread starter Thread starter aznyukiannai
  • Start date Start date
  • Tags Tags
    Load
AI Thread Summary
Rated load refers to the maximum power output a transformer is designed to handle, measured in VA (volt-amperes). It is related to rated voltage and current, with the understanding that the actual power output can vary based on the load's power factor. For a transformer operating at rated load, the heat generated from current flow through the windings is a critical consideration. At rated voltage and current, the transformer achieves 100% of its rated load in kVA, but only 80% in kW due to a power factor of 0.8. The clarity of the quiz question regarding input voltage may be lacking, as it does not specify the type of load being referenced.
aznyukiannai
Messages
1
Reaction score
0
What is "rated load"?

What is "rated load" and what is its relationship to rated voltage and current?

Part of the question:
"Assume the transformer is supplying rated load at 480 V and 0.8 PF lagging. What is the transformer's input voltage?"

I'm not asking for help with actually working out the problem, I just need to know what that term means. Any help is welcome. Thanks!
 
Engineering news on Phys.org
Rated load is the maximum power output the transformer was designed to handle.

How are rated voltage and current related to power?
 
A transformers "rated load" is rated in VA (volts X amps), not power (since the manufacturer has no idea what kind of load will be put on it).

The rating of the transformer is based on the heat build up from current flow through the windings. At rated voltage and rated amps, you would have 100% of rated load in terms of kva, but only 80% Kw with a .8 power factor.
Without knowing which they are referring to in terms of "load", the voltage part of the question is irrelevant.

If the quiz question is stated correctly in your post, it is poorly worded.
 

Thread 'Why does the amperage go real high if there is a low voltage short?'

I used to be an HVAC technician. One time I had a service call in which there was no power to the thermostat. The thermostat did not have power because the fuse in the air handler was blown. The fuse in the air handler was blown because there was a low voltage short. The rubber coating on one of the thermostat wires was chewed off by a rodent. The exposed metal in the thermostat wire was touching the metal cabinet of the air handler. This was a low voltage short. This low voltage...
View full post »
Thread 'How Does Jaguar's 1980s V12 Dual Coil Ignition System Enhance Spark Strength?'

Thread 'How Does Jaguar's 1980s V12 Dual Coil Ignition System Enhance Spark Strength?'

I have come across a dual coil ignition system as used by Jaguar on their V12 in the 1980's. It uses two ignition coils with their primary windings wired in parallel. The primary coil has its secondary winding wired to the distributor and then to the spark plugs as is standard practice. However, the auxiliary coil has it secondary winding output sealed off. The purpose of the system was to provide a stronger spark to the plugs, always a difficult task with the very short dwell time of a...
View full post »

Similar threads

Sizing an Isolation Transformer for a DC Power Supply
Replies
8
Views
2K
Transformer load reading calculation
Replies
4
Views
3K
Generator load sharing
Replies
4
Views
2K
Maximum power from a transformer
Replies
8
Views
3K
DC input random offset voltage for diff. amplifier with current-mirror load
Replies
2
Views
1K
Which is the correct diagram (synchronous alternator varying PF)
Replies
11
Views
3K
How to get the fuse rating you need for a DC power supply
Replies
3
Views
4K
Why is Rated Voltage Used for Full Load Voltage Regulation Calculations?
Replies
2
Views
3K
What's the normal low-load working temperature for an SMPS transformer?
Replies
27
Views
5K
High Pass Filter Working Principle
Replies
15
Views
2K

Hot Threads

Recent Insights

Back
Top