Geekzone: technology news, blogs, forums
Guest
Welcome Guest.
You haven't logged in yet. If you don't have an account you can register now.




565 posts

Ultimate Geek


# 183704 27-Oct-2015 12:36
Send private message

I have a Japanese device which lists a power rating of 100V 500VA.

The device is plugged into a to a 240v to 100v 1000VA step down transformer (which comes with the device from the manufacturer).

A power meter measures the device power consumption at <200W (~130W) at the wall (inc transofrmer).

I'm looking to protect the device with a UPS for 3-5min and want to confirm size of the UPS I should be looking at.

Should I go by the measured consumption of 200W, the device rating of 500VA or transformer rating of 1000VA?

Create new topic
195 posts

Master Geek

Subscriber

  # 1415070 27-Oct-2015 20:35
Send private message

What kind of device is it? If it's motorised, you may need a UPS capable of delivering much more current than a simple P=EI calculation would suggest.

Does your power meter tell you the power factor of your device?

22920 posts

Uber Geek

Trusted
Subscriber

  # 1415095 27-Oct-2015 21:30
Send private message

UPS's usually are a pretty bad inverter in them, and that makes transformers unhappy. The 24V AC one for my sprinkler controller cooked itself on the last power outage when it was running on the UPS. Not sure how the stepdown would get on with that.

What on earth needs a stepdown transfromer and a UPS tho?




Richard rich.ms

 
 
 
 


1031 posts

Uber Geek


  # 1415101 27-Oct-2015 21:35
Send private message

If you have measured the total power consumption at ~200 W at source then that includes all conversions in the transformer.

Does the consuming device have the ability to operate in any other modes that draw more power ? What is it?
For example , was it a thing that had already heated up? If the load device goes into a mode and draws 500VA while on UPS, the backup time will drop to 40% of the time you think you're going to get at 200W(~VA).

The transformer rating is irrelevant to your UPS requirement as it only determines the maximum transformer load. Load is maximum 500 W(~VA), typical 200 W.



Create new topic



Twitter and LinkedIn »



Follow us to receive Twitter updates when new discussions are posted in our forums:



Follow us to receive Twitter updates when news items and blogs are posted in our frontpage:



Follow us to receive Twitter updates when tech item prices are listed in our price comparison site:





News »

Vodafone New Zealand starts two year partnership with LetsPlay.Live
Posted 28-Jan-2020 11:24


Ring launches indoor-only security camera
Posted 23-Jan-2020 17:26


New report findings will help schools implement the digital technologies curriculum content
Posted 23-Jan-2020 17:25


N4L to upgrade & support wireless internet inside schools
Posted 23-Jan-2020 17:22


Netflix releases 21 Studio Ghibli works
Posted 22-Jan-2020 11:42


Vodafone integrates eSIM into device and wearable roadmap
Posted 17-Jan-2020 09:45


Do you need this camera app? Group investigates privacy implications
Posted 16-Jan-2020 03:30


JBL launches headphones range designed for gaming
Posted 13-Jan-2020 09:59


Withings introduces ScanWatch wearable combining ECG and sleep apnea detection
Posted 9-Jan-2020 18:34


NZ Police releases public app
Posted 8-Jan-2020 11:43


Suunto 7 combine sports and smart features on new smartwatch generation
Posted 7-Jan-2020 16:06


Intel brings innovation with technology spanning the cloud, network, edge and PC
Posted 7-Jan-2020 15:54


AMD announces high performance desktop and ultrathin laptop processors
Posted 7-Jan-2020 15:42


AMD unveils four new desktop and mobile GPUs including AMD Radeon RX 5600
Posted 7-Jan-2020 15:32


Consolidation in video streaming market with Spark selling Lightbox to Sky
Posted 19-Dec-2019 09:09



Geekzone Live »

Try automatic live updates from Geekzone directly in your browser, without refreshing the page, with Geekzone Live now.


Support Geekzone »

Our community of supporters help make Geekzone possible. Click the button below to join them.

Support Geezone on PressPatron



Are you subscribed to our RSS feed? You can download the latest headlines and summaries from our stories directly to your computer or smartphone by using a feed reader.

Alternatively, you can receive a daily email with Geekzone updates.