Singapore Expats Forum

Challenge of Voltage/Digital standards differences between USA and Singapore

Discuss about computers & Internet. Including mobile phones, home appliances & other gadgets. Read about Windows security risks or virus updates.
watours
Newbie
Newbie
Posts: 6
Joined: Tue, 13 Sep 2016

Challenge of Voltage/Digital standards differences between USA and Singapore

Postby watours » Tue, 13 Sep 2016 3:45 pm

hallenge of Voltage/Digital standards differences between USA and Singapore

Hello, I recently moved from USA to Singapore and my love for my 5 year old 65 inch plasma TV forced me to bring it along with me. After doing a lot of research, I thought I had covered all bases to address the voltage and digital standards differences between the 2 countries but every time i connect a local set-top-box to my TV via HDMI, my apartment's circuit breaker keeps tripping.

I bought a step down transformer (220->110 V) and PAL->NTSC converter and here are the steps I followed:

1. Connected step down transformer to Main Supply (220v) - > ok
2. Connected TV to transformer (110v) - > ok (tv switched on)
3. Connected Apple Tv (from US) to Main Supply (220v) - > ok (apple supports 110-220v)
4. Connected Apple Tv (from US) to TV via HDMI - > ok (works)
5. Connected Local Set-top box (from Singapore) to Main supply (220v) - > ok (powers up)
And Finally,
6. Connected Local Set-top box (from Singapore) to TV via HDMI -> circuit breaker trips

I cannot seem to understand what goes wrong every time i connect the set-top box to the TV. They have replaced the set-top-box with another but the issue still remains. I have tried plugging the set-top box to the converter (it supports 110-220v) and then connect to the TV but the issue still remains. Can anyone shed any light on how I investigate or fix this? Are there different HDMI standards in different regions? Any help will be greatly apprciated.

User avatar
PNGMK
Governor
Governor
Posts: 5668
Joined: Thu, 21 Mar 2013
Location: Sinkapore

Re: Challenge of Voltage/Digital standards differences between USA and Singapore

Postby PNGMK » Tue, 13 Sep 2016 6:06 pm

US appliances often have the neutral connected to the earth internally - why? I don't know but probably something to do with Thomas Edison who was an idiot who founded the company I work for. This needs to be disconnected somehow - it's not enough to use a two wire power connection as the chassis will then be connected to neutral (which is easily swapped with live through bad wiring practices or use of two pin plugs). At some point here the chassis earth is being connected to real earth (probably via hooking up the set top box) and that's tripping the ELCB as N is now to E. Find someone semi intelligent who owns a DMM and is confident enough to trace through the internal PSU wiring or use an isolation transformer. Paging SE who will no doubt begin an electrical standards debate with me. AS3000 for the win!
Last edited by PNGMK on Tue, 13 Sep 2016 6:08 pm, edited 1 time in total.
IANAL. IANACPA. IANA Teacher.
Arrested? Lawyer Up
International School job? School website or http://www.ISS.edu
School advice? Avoid for profit schools
Tax advice? CPA
Pay me $5k for 100% success filling in PR form!

User avatar
PNGMK
Governor
Governor
Posts: 5668
Joined: Thu, 21 Mar 2013
Location: Sinkapore

Re: Challenge of Voltage/Digital standards differences between USA and Singapore

Postby PNGMK » Tue, 13 Sep 2016 6:07 pm

Oh if you're wondering what neutral connected to earth means - it means the ELCB sees leakage to earth (essentially an imbalance between L and N) and trips the breaker.
IANAL. IANACPA. IANA Teacher.
Arrested? Lawyer Up
International School job? School website or http://www.ISS.edu
School advice? Avoid for profit schools
Tax advice? CPA
Pay me $5k for 100% success filling in PR form!

User avatar
Strong Eagle
Moderator
Moderator
Posts: 11050
Joined: Sat, 10 Jul 2004
Location: Off The Red Dot
Contact:

Re: Challenge of Voltage/Digital standards differences between USA and Singapore

Postby Strong Eagle » Tue, 13 Sep 2016 9:19 pm

Are you sure it's a circuit breaker and the the ground fault circuit interrupt breaker? Most all houses and apartments in Singapore are equipped with a GFCI breaker. I would tend to agree with PNGMK.

Have you tried reversing the plug in the outlet for the set top box? I bet your problem will go away.

watours
Newbie
Newbie
Posts: 6
Joined: Tue, 13 Sep 2016

Re: Challenge of Voltage/Digital standards differences between USA and Singapore

Postby watours » Wed, 14 Sep 2016 11:15 am

Strong Eagle wrote:Are you sure it's a circuit breaker and the the ground fault circuit interrupt breaker? Most all houses and apartments in Singapore are equipped with a GFCI breaker. I would tend to agree with PNGMK.

Have you tried reversing the plug in the outlet for the set top box? I bet your problem will go away.


Here is the image of the circuit breaker that trips everytime i connect the set top box. I reversed the plug in the outlet and unfortunately it didn't fix the problem.
Attachments
IMG_1723.JPG

watours
Newbie
Newbie
Posts: 6
Joined: Tue, 13 Sep 2016

Re: Challenge of Voltage/Digital standards differences between USA and Singapore

Postby watours » Wed, 14 Sep 2016 11:33 am

PNGMK wrote:US appliances often have the neutral connected to the earth internally - why? I don't know but probably something to do with Thomas Edison who was an idiot who founded the company I work for. This needs to be disconnected somehow - it's not enough to use a two wire power connection as the chassis will then be connected to neutral (which is easily swapped with live through bad wiring practices or use of two pin plugs). At some point here the chassis earth is being connected to real earth (probably via hooking up the set top box) and that's tripping the ELCB as N is now to E. Find someone semi intelligent who owns a DMM and is confident enough to trace through the internal PSU wiring or use an isolation transformer. Paging SE who will no doubt begin an electrical standards debate with me. AS3000 for the win!


Also, i have noticed another interesting quirk. I have connected my step down transformer to a fancy belkin surge protector that i have been using for some time. It has two indicators that read "Protected" and "Not Grounded".

I noticed that the "Not Grounded" LED glows up when i connect the surge protector to the step down transformer; However, when i connect the surge protector directly to the mains, the "Not Grounded" light stays off. It seems to me that the transformer is somehow screwing up the grounding voltage and it might be causing issues. So I had a couple of questions that i hope you guys can guide me on:

1. Seeing the "Not Grounded" LED behavior, does it make sense to buy another transformer that does not have the grounding problem?
2. Assuming the transformer is the problem, why would my Apple TV work (through HDMI) when its connected to main supply? shouldn't it face the same problem as the STB?

User avatar
Strong Eagle
Moderator
Moderator
Posts: 11050
Joined: Sat, 10 Jul 2004
Location: Off The Red Dot
Contact:

Re: Challenge of Voltage/Digital standards differences between USA and Singapore

Postby Strong Eagle » Wed, 14 Sep 2016 12:25 pm

watours wrote:
Strong Eagle wrote:Are you sure it's a circuit breaker and the the ground fault circuit interrupt breaker? Most all houses and apartments in Singapore are equipped with a GFCI breaker. I would tend to agree with PNGMK.

Have you tried reversing the plug in the outlet for the set top box? I bet your problem will go away.


Here is the image of the circuit breaker that trips everytime i connect the set top box. I reversed the plug in the outlet and unfortunately it didn't fix the problem.


This is definitely a GFCI device... a ground fault interrupt circuit breaker. You are experiencing a ground leak somewhere and based upon your post to PNGMK below, I'd say you have a faulty transformer.

User avatar
PNGMK
Governor
Governor
Posts: 5668
Joined: Thu, 21 Mar 2013
Location: Sinkapore

Re: Challenge of Voltage/Digital standards differences between USA and Singapore

Postby PNGMK » Wed, 14 Sep 2016 12:58 pm

Without knowing if the step down transformer is an auto transformer or a standard type I really can't comment. Take a picture of it and post it. This is all point to a ground loop or earth leakage issue as I suspected. Also can you post the model number of the TV?
IANAL. IANACPA. IANA Teacher.
Arrested? Lawyer Up
International School job? School website or http://www.ISS.edu
School advice? Avoid for profit schools
Tax advice? CPA
Pay me $5k for 100% success filling in PR form!

watours
Newbie
Newbie
Posts: 6
Joined: Tue, 13 Sep 2016

Re: Challenge of Voltage/Digital standards differences between USA and Singapore

Postby watours » Wed, 14 Sep 2016 1:21 pm

PNGMK wrote:Without knowing if the step down transformer is an auto transformer or a standard type I really can't comment. Take a picture of it and post it. This is all point to a ground loop or earth leakage issue as I suspected. Also can you post the model number of the TV?


The transformer is:
Goldsource STU-1000 Step Up/Down Voltage Transformer Converter - AC 110/220 V - 1000 Watt
Here's link to its amazon page: https://www.amazon.com/Goldsource-STU-1 ... B003OPFJD6

And the model# of the TV is PND8000
Here's a link to the product page: http://www.samsung.com/us/support/owner ... D8000FFXZA
Attachments
Transformer.jpg

User avatar
PNGMK
Governor
Governor
Posts: 5668
Joined: Thu, 21 Mar 2013
Location: Sinkapore

Re: Challenge of Voltage/Digital standards differences between USA and Singapore

Postby PNGMK » Wed, 14 Sep 2016 1:51 pm

Mmm. I bet that's an auto transformer but can't be sure without a meter. I'd recommend something like this https://www.amazon.com/ACUPWR-AUD-1500- ... ransformer
IANAL. IANACPA. IANA Teacher.
Arrested? Lawyer Up
International School job? School website or http://www.ISS.edu
School advice? Avoid for profit schools
Tax advice? CPA
Pay me $5k for 100% success filling in PR form!

User avatar
PNGMK
Governor
Governor
Posts: 5668
Joined: Thu, 21 Mar 2013
Location: Sinkapore

Re: Challenge of Voltage/Digital standards differences between USA and Singapore

Postby PNGMK » Wed, 14 Sep 2016 1:53 pm

side topic: what's the problem with auto transformers you ask? they don't isolate - they use a single coil and take a tap off it to step down - they are extremely risk to use as if the winding fuses you end up with 220V on the output. Secondly they do not isolate - which creates the possibility of ground loops as we see here.
IANAL. IANACPA. IANA Teacher.
Arrested? Lawyer Up
International School job? School website or http://www.ISS.edu
School advice? Avoid for profit schools
Tax advice? CPA
Pay me $5k for 100% success filling in PR form!

User avatar
PNGMK
Governor
Governor
Posts: 5668
Joined: Thu, 21 Mar 2013
Location: Sinkapore

Re: Challenge of Voltage/Digital standards differences between USA and Singapore

Postby PNGMK » Wed, 14 Sep 2016 1:54 pm

IANAL. IANACPA. IANA Teacher.
Arrested? Lawyer Up
International School job? School website or http://www.ISS.edu
School advice? Avoid for profit schools
Tax advice? CPA
Pay me $5k for 100% success filling in PR form!

User avatar
Strong Eagle
Moderator
Moderator
Posts: 11050
Joined: Sat, 10 Jul 2004
Location: Off The Red Dot
Contact:

Re: Challenge of Voltage/Digital standards differences between USA and Singapore

Postby Strong Eagle » Wed, 14 Sep 2016 8:12 pm

PNGMK wrote:side topic: what's the problem with auto transformers you ask? they don't isolate - they use a single coil and take a tap off it to step down - they are extremely risk to use as if the winding fuses you end up with 220V on the output. Secondly they do not isolate - which creates the possibility of ground loops as we see here.


Bingo! Hadn't thought about that style of transformer and I was wondering how come he wasn't isolated when he has a step down transformer in the mix. Also very dangerous if you happen to be part of the ground loop.

User avatar
x9200
Moderator
Moderator
Posts: 9313
Joined: Mon, 07 Sep 2009
Location: Singapore

Re: Challenge of Voltage/Digital standards differences between USA and Singapore

Postby x9200 » Wed, 14 Sep 2016 9:16 pm

This is a bigger brother (STU-2000) of the said transformer, the secondary side:
Image

The winding wire seems pretty thick. Can it still be an autotransformer with such thick wire?

On the other hand, it's cheap. Probably too cheap.
I also have at home a smaller model (200w, different brand) with identical external design. Mine is definitely an autotransformer.

User avatar
PNGMK
Governor
Governor
Posts: 5668
Joined: Thu, 21 Mar 2013
Location: Sinkapore

Re: Challenge of Voltage/Digital standards differences between USA and Singapore

Postby PNGMK » Thu, 15 Sep 2016 10:53 am

X9200 - unplug everything. Put an ohmeter on the N or L side of the primary and check the resistance to L and N of the secondary. If you see Ohms instead of M Ohms you have an auto transformer. I can't tell from the windings alone. A true isolation transformer should show M Ohms between the primary and secondary side (unless N on both sides has been tied to earth or commoned).
IANAL. IANACPA. IANA Teacher.
Arrested? Lawyer Up
International School job? School website or http://www.ISS.edu
School advice? Avoid for profit schools
Tax advice? CPA
Pay me $5k for 100% success filling in PR form!


  • Similar Topics
    Replies
    Views
    Last post

Return to “Computer, Internet, Phone & Electronics”

Who is online

Users browsing this forum: No registered users and 1 guest