First off, where are you? I can't figure if it's here in the US or maybe the UK.

Second, ALL the things you mentioned are NOT heavy draw items. Even the printer (unless it's a laser) will not draw anything unless it's working on something. The thing that will draw a lot is the vacuum that you said you use sometimes.
The clock is most likely one of the smallest draws so I doubt that's an issue, but the 120/220 things gets me. Are you using it at it's intended voltage? Is there a selector switch, or does it choose automatically?

I think you just have too much plugged in in other areas. I bet this circuit covers far more area than the one you were using previously.
If you saw what I have plugged into ONE 20A circuit in my home office, including an 8kBTU window unit, you'd be amazed that I have NEVER tripped a breaker in there.

Well, you can try disconnecting different things (like the clock) and see if the tripping goes away. You may have one thing that is drawing an excessive power. The other answer is you have too much stuff plugged in . Shutting off or moving to another room will help that.

While it's possible that the breaker is a problem, it's not high on the list of likely issues. An electrician can measure the current on the wire and see if you have that much load.

Thank you for the quick reply. I live in Texas.
I bought the clock from India - It automatically does the 220v/110v. I had to add the flat pin for US. India we use the round pin plugs.
This circuit also covers another room in upstairs. Nothing in that room - except a small table fan.

Do you think, the clock damaged the circuit?

My other question is - why does it take couple of hours to get the power after I turn the breaker on. The power does not come immediately - few hours later the power comes back to the room.

The breaker does not look like a normal size. In the entire circuit box, I have 4 of them like this size. Everything else is normal size.

Ooooohhh. Wow! That changes things.
The power should come back on immediately after resetting the breaker.

You have a problem somewhere in this circuit. I would open every box and check every splice and device on this circuit to check for bad connections or shorts.

This circuit takes care of the plug points for 2 rooms. So, I have to open all the plug points. How do I find if the breaker is gone bad.

It is a bad connection somewhere in the circuit. Check all connections. It is most likely not the breaker unless the bad connection happens to be at the breaker but most likely it is in a device box.

Circuit breaker has not turned on yet. No power in the outlets. I have started opening the boxes. No issues so far?

Are you asking us whether there are any issues so far?!?
Shouldn't you be telling us that? :)

How are you testing for power?
Did you test right at the breaker first? There should be power there.
Then move on to the outlet that is most likely the first one along the way. Is there power there? And so on.

Or are you just randomly opening outlets, poking around, and moving on?

This post was edited by greg_2010 on Wed, Feb 26, 14 at 10:35

This circuit covers totally 6 outlets in two rooms. I opened two in one room, did not find any. But, I went back and pressed the test button in the breaker - it tripped - then off, then on again. Checked for the power in one room, nothing. Went to the second room and saw the table fan was plugged in. Pulled the plug from the outlet.
Now checked again - power is back.

So, I plugged these - desktop computer, monitor, an audio system, laptop power card. (Through two surge protection power boxes from one outlet - two plugged in two)
Things were working fine. Now plugged the laser printer and turned on..

It tripped again. What could cause? same way when we tried to connect the vaccum cleaner the power tripped.

Am I overloading?

I opened two in one room, did not find any.
Did not find any what?

I went back and pressed the test button in the breaker
Is this a GFCI or AFCI breaker?

Checked for the power in one room
How are you checking for power?

Pulled the plug from the outlet. Now checked again - power is back.
Immediately? Or did you go back and flip the circuit breaker again?

Details matter. Please be as clear as you can about the sequence of events and what exactly you are doing.

I opened two in one room, did not find any.
Did not find any what?
I was trying to see if there is any burn out or loose connection etc. Nothing I can find though

I went back and pressed the test button in the breaker
Is this a GFCI or AFCI breaker?
AFCI -breaker

Checked for the power in one room
How are you checking for power?
I have a power outlet checker and a small night lamp. Power outlet checker - shows no lights on - means all three lights are off. Night lamp did not turn on

Pulled the plug from the outlet. Now checked again - power is back.
Immediately? Or did you go back and flip the circuit breaker again?

Yes immediately - the breaker was already flipped on.

---
Here is additional information.
I found the Brother laser printers have issues with AFCI breakers - lots of talk in the forum. Some recommended changing the Breaker - because it might have been weak.
So went to lowes - purchased a brand new ($42) AFCI breaker and installed - same Square D brand.
Testing worked fine - it flipped - I turned it off then turned it on again - No power :-(
Even with the new breaker ??

The fact that it seems to randomly come on and off implies that there is a loose connection somewhere.
When you are checking for loose connections, what exactly are you doing? Are you tightening screws, removing wirenuts and reapplying them? Hopefully you are doing that with the power turned off.
Or are you just looking at them?

Have you checked the outlet where the table fan was plugged in? Perhaps when you unplugged it, it wiggled the outlet and the loose connection temporarily re-established itself.
Turn the power off, open up that outlet and check the connections there. Move any backstabbed wires on the outlet to the screw connections on the side.

Thank you for the quick reply. If there was loose connection, the breaker should trip right? I'll open the outlet.
Yes the breaker was off when I was opening the outlets.

Hire an electrician. Just realize how much you are struggling to solve the problem and how important it is to fix the problem. Not just for your peace of mind and convenience, but in case of any safety risk there may be with the current condition. Now when he comes in to fix the proplem and presents you with the invoice, remember how difficult it is to diagnose the problem and how important it is for it to be fixed. I have had customers say "I have had my uncle and cousin over here for 2 days tearing things apart to find the problem with no success." I walk in, diagnose the problem, make the necessary repairs and present them with an invoice. Then, here it comes, "why is it so much? You were only here less than an hour." All of a sudden I made it look easy and not worth paying me my service call rate. I am not shy about saying " You are paying for the 20+ years of knowledge and experience, a truck full of tools and meters, insurance, license and all the other things that made it possible for me to come here to help you today. It is not just about the hour it took to fix the problem."

I agree. The money is for the experience. By the way, I was able to find the outlet - it was slightly burned. Replaced that outlet - now the breaker works the it suppose to. on/off when I flip the switch. Still the new breaker is on - I probably leave the new one - just to eliminate the 'weak breaker' point.
All are working fine. Hopefully, this continues. Thank you for the help.

BROTHER LASER PRINTER TRIPPING AFCI FINAL END-ALL SOLUTION.

Brother knows most all of their laser printer fusers trip AFCI breakers multiple times hack-to-back fefore they actually print because they simulate an "arc" at startup, END OF STORY. I have spoken to tech support all I am going to. They take you thru an endless series of questions (device printing from, how many devices on the printer circuit, over loaded circuit and all of the other really ignorant questions). They refuse to admit their fuser control design is the culprit.

I had to resort to a solution the industry as a whole, forced me into, which was to replace the AFCI breaker with a non-AFCI breaker. I am really aggravated I was forced into this solution because I also had to use an insulated butt connector to extend the black conductor to reach the replacement breaker which is not to code either. Furthermore, Brother refuses to, or can't recommend a printer which won't trip the AFCI. They tell the customer that ALL laser printers do this as well. If that were true, NO ONE would purchase one.