[Prowler]

Originally Posted by graaja

Hi All,

I need some inputs about a UPS.


I recently got a 2kVA pure sine wave UPS from a company in Coimbatore called Kondaas. The UPS is rated for 1400W of load. The peak load in the UPS circuit at home is about 1200W, but under normal use case, the load would be around 600W.

Everything works fine except for one issue. When the grid supply is off and the loads are powered by the UPS, if I turn on the TV or the home theater system (a 5.1 Denon system with a subwoofer), the UPS trips. TV and home theater draw a combined power of 180W. I measured the in rush current during turn on, and it is about 8A each for the TV and home theater. This is almost 1.6kW of in rush power requirement.



Now my questions:

1. Is there any 2kVA pure sine wave UPS that can take 150% overload for a few hundred milliseconds?
2. Does anyone have a similar experience of UPS tripping when turning on electronic loads that have SMPS power supply inside? If yes, did you find a solution?
3. I have an idea that if I can find a soft start circuit that can limit in rush current, this tripping problem can be solved. Has anyone used such a soft start circuit?

I have an idea which may or may not work in your case. When we had CRT TVs and Monitors in the distant past and where we had to connect them to the UPS all at the same time, some times, the 3 KVA UPS used to trip because of the momentary overload from the degausser circuitry in each of these CRT monitors/TVs. We disconnected the degausser circuit temporarily but ended up with horrible color cast. So we came up with an idea:
Add a 300 W flood light tungsten bulb in series with each offending monitors. The initial surge would be reduced to that of the 300 W and the bulb would light momentarily. But no tripping now. Under normal circumstances as the original load is several times less than the series connected bulb, the load will face a few volts drop - nothing to crib about.

The only issue is the cost of adding the 300 W or higher rated bulb in your case. You may need to size the bulb as per your actual load.

[sagarpadaki]

Originally Posted by graaja

Hi All,


Everything works fine except for one issue. When the grid supply is off and the loads are powered by the UPS, if I turn on the TV or the home theater system (a 5.1 Denon system with a subwoofer), the UPS trips. TV and home theater draw a combined power of 180W. I measured the in rush current during turn on, and it is about 8A each for the TV and home theater. This is almost 1.6kW of in rush power requirement.

The problem occurs only during cold start of the TV or home theater when the backup power is already on.

Can you check adding a voltage stabilizer between the power supply and the DENON? I faced a similar problem with my TV and 1000VA APC UPS. In fact it used to happen even during warm switches to UPS power. I added a voltage stabilizer and a spike buster to protect the TV from surges that started occurring frequently in my locality and the tripping problem got solved!

Maybe worth a shot if you have a stabilizer of the rated output already available in home.

[graaja]

Originally Posted by Prowler

I have an idea which may or may not work in your case.
...
The only issue is the cost of adding the 300 W or higher rated bulb in your case. You may need to size the bulb as per your actual load.

Originally Posted by sagarpadaki

Can you check adding a voltage stabilizer between he power supply and the DENON?
...
Maybe worth a shot if you have a stabilizer of the rated output already available in home.

Thanks a ton, Prowler and sagarpadaki. These are awesome ideas. I will give these a try soon and update.

[Mortis]

Guys I need suggestions on a new 750W Mixer grinder. Any particular brand to go for ? Philips is kind of like Maruti, just about ok with decent availability of spares for repair.
Other than philips how are
Morphy Richards (not so good experience with irons)
Tefal
Borosil
Crompton
Bajaj
Havells
Panasonic (quite a bit more expensive)

[Thad E Ginathom]

Originally Posted by Mortis

Guys I need suggestions on a new 750W Mixer grinder. Any particular brand to go for ? ... ... ...

We have a Prestige. I'm glad to say that we have been able to get spares for it, but I wish I had bought one of the "more Indian" brands from a shop, where you see the spares stacked up on the shelf!

[dailydriver]

Originally Posted by Mortis

Guys I need suggestions on a new 750W Mixer grinder

Any talk about mixer grinders that excludes Preethi would be incomplete. Purchase any of its Blue Life models and you will not go wrong. That said, Panasonic also offers sturdy and long lasting models; good blades, push buttons and unique jar locking mechanisms distinguish them from others.

No affiliations!

[Sebring]

We got the first Panasonic when it was launched a decade back, nothing seems to go wrong with this. There was a marriage in the family so I gifted this model that comes in premium Gold. It's expensive, certainly, but very reliable. Needless to say, feedback is excellent, from the 'giftee'. LOL

Originally Posted by Mortis

Guys I need suggestions on a new 750W Mixer grinder.

[shamanth]

Originally Posted by Mortis

Guys I need suggestions on a new 750W Mixer grinder. Any particular brand to go for ? Philips is kind of like Maruti, just about ok with decent availability of spares for repair.
Other than philips how are
Morphy Richards (not so good experience with irons)
Tefal
Borosil
Crompton
Bajaj
Havells
Panasonic (quite a bit more expensive)

Once you try Preethi mixers you wont look for other brands, tough and reliable. No other brands come closer.

[Latheesh]

Surprised that no one mentioned SUJATA. We have their Dynamix DX 900 model and it is awesome.

[diyguy]

We have found Preethi to be extremely loud and bordering on damage to hearing. Shifted back to Philips this year only due to the noise.
We also have a Kenwood, purchased abroad, that is a food processor and extremely gentle on the ears. The Mrs uses that when she cooks and does not give it to the help.

[thenomad]

Originally Posted by Mortis

Guys I need suggestions on a new 750W Mixer grinder. Any particular brand to go for ?

If there is good presence of Elgi Ultra in your city, then I would suggest you look at Elgi Ultra Duramix as well. Very nice mixers and build quality is superior. They come with metal couplers in jar and motor, SS body and many more.

[Mortis]

Thanks for all the suggestions. I'll look into it and report back

[carboy]

My washing machine has started giving a very mild shock when I touch the soap compartment (it's plastic!).

Where can the problem be? In the washing machine or in the electrical plug point where it is attached? It's a regular 3 pin plug - so I assume it's earthed & shouldn't give a shock.

[graaja]

Originally Posted by carboy

My washing machine has started giving a very mild shock when I touch the soap compartment (it's plastic!).

Where can the problem be? In the washing machine or in the electrical plug point where it is attached? It's a regular 3 pin plug - so I assume it's earthed & shouldn't give a shock.

My first suspect would be the plug point. Either the earth has become weak or disconnected, or the neutral has a lose connection. Have the plug point checked first.

[BaCkSeAtDrIVeR]

Originally Posted by graaja

My first suspect would be the plug point. Either the earth has become weak or disconnected, or the neutral has a lose connection. Have the plug point checked first.

Shouldn't the MCB trip?