Jump to content
BANGKOK 22 May 2019 05:33
Crossy

VEG Automatic Voltage Regulator - The Saga

Recommended Posts

EDIT I've split this AVR Saga off from the other AVR thread, any issues with VEG AVRs please put here.

 

Well, our VEG 20000 has decided to stop regulating 😞

 

With the juice off I cannot move the variac brush so something is jammed.

 

Time to bypass the beast and investigate the gearbox 😞

 

  • Sad 1

Share this post


Link to post
Share on other sites

I hope you are succes full in repairing it!

 

According to my local Global House they have a lot of bad experiences with VEG, and they are absolute not happy with the support from VEG when something goes wrong (what seems to be often) 

 

The staff has received the order to not sale them anymore. They are still on display, as it is a company rule.

 

In case you buy a new one, I am very happy with my new one:

CBC ZTY-20KVA/1. I was also happy with my VEG when it worked, but even when compare both when they are new, the CBC has some advantages. It responses faster (much faster), although it is sometimes a bit slow with regulating the voltage back when after a low voltage the voltage is going up again. The biggest advantage from the CBC compared to the VEG is that it is much more quiet. The fans only run when neccessary, while from the VEG they are runing when you power it on, even without a load. For that reason I placed the CBC downstairs, not knowing it is much more quiet. (First the AVR was placed close to my bed.....) 

 

Big disadvantage can be that it is more expansive, I paid 24.500 Baht.

 

Arjen.

Share this post


Link to post
Share on other sites
10 minutes ago, Arjen said:

I hope you are succes full in repairing it!

Job for the weekend to bypass the beast and pull the motor and gearbox, we shall see what's amiss then.

 

EDIT I suppose I'm lucky in having the time, tools, knowledge and enthusiasm to fix this sort of thing. I will of course post photos of the issues found and my fixes.

 

  • Like 2

Share this post


Link to post
Share on other sites
25 minutes ago, Crossy said:

 

EDIT I suppose I'm lucky in having the time, tools, knowledge and enthusiasm to fix this sort of thing. I will of course post photos of the issues found and my fixes.

 

I was "unlucky" it was still under warrantly. So had not much of a choice then bring it to global. They replaced the faulty part (they said) they "tested" it when I picked it up ("testing" by connecting the input, no load at all) While connecting the wires they made a big short, what gives all an indication about the available knowledge.

 

After connecting at home it still did not work. So then they refund me.... By the way, my variac was also not rotatable by hand, and also an other modell in the shop was not rotatable, I know you told me yours was moveable, but that seems not with all the case.

 

Arjen.

 

Share this post


Link to post
Share on other sites
1 minute ago, Arjen said:

I know you told me yours was moveable, but that seems not with all the case.

Yup, ours definitely was moveable by hand, now it's not. Of course this could be a red herring. 

Share this post


Link to post
Share on other sites

Do you think removing the brush arm might have released some kind of stiction?  Also, did you notice the pot or whatever controls the thing?  (I still haven't gotten around to taking the cover off of mine.)

Share this post


Link to post
Share on other sites
2 hours ago, bankruatsteve said:

Do you think removing the brush arm might have released some kind of stiction?

Almost certainly, it's just not obvious where it was. Nothing visible on the bearing face of the variac.

 

We shall just have to watch the beast and see how it behaves.

 

It is nice to know that a stalled variac motor doesn't kill the driver electronics 🙂

 

  • Like 1

Share this post


Link to post
Share on other sites

A quick bump of this thread as the AVR had a bit of a wobbler last week.

 

Family visit so all the A/C was running (I found out later that the UK-ites had it set to 16C in the bedrooms - power bill was 8,200 Baht) middle of the night the genset started, rest of the village still on. Quick investigation showed the incoming mains fine but the AVR with no output.

 

I was just just about to decide how to bypass the beast in the middle of the night when - tada - it turned on. It did feel somewhat warm (suspected overheat) so I opened the front door, aimed a fan inside and went back to bed. It didn't go off again and was happy for the rest of the family visit (still with the door open and the fan pointing inside).

 

Now the family have left time to investigate.

 

There's a little baby fan on the variac brush (along with a thermal switch which is probably what killed the output), it was not rotating (seized solid). There was a replacement 12V fan in my "keep it for a rainy day" box, 30 mins later that's installed and going round.

 

Looking into the bowels of the beast revealed that the main ventilation fan also wasn't going round (220V 4" fan), this one wasn't seized, but was open circuit (burned out). A replacement was again rustled up from my magic box. Worked fine but was a LOT more noisy than the original (it lives in the corner of the lounge and was disturbing my enjoyment of the IPL). Bunged a 1uF 250V AC motor run capacitor in series which dropped the fan voltage down to about 120V, it's still moving air but is much quieter.

 

So we are back online, I'm a bit miffed that the fans failed after less then 2 years (cheap Chinese) but the replacements are better quality so with luck that's something else to not go wrong.

 

Next job is to add a thermostat to the main fan so it only runs when the box is getting warm, one of these is on order https://www.aliexpress.com/item/W3001-W3002-W3230-LED-Digital-Thermostat-Temperature-Controller-AC-110V-220V-DC12V-24V-Thermoregulator-Heating-Cooling/33004698151.html the W3001 220V version.

 

HTB1DfE5Rr2pK1RjSZFsq6yNlXXao.jpg

So the fan can run at full speed only when needed.

 

 

 

 

 

 

Share this post


Link to post
Share on other sites
28 minutes ago, Crossy said:

A quick bump of this thread as the AVR had a bit of a wobbler last week.

 

Family visit so all the A/C was running (I found out later that the UK-ites had it set to 16C in the bedrooms - power bill was 8,200 Baht) middle of the night the genset started, rest of the village still on. Quick investigation showed the incoming mains fine but the AVR with no output.

 

I was just just about to decide how to bypass the beast in the middle of the night when - tada - it turned on. It did feel somewhat warm (suspected overheat) so I opened the front door, aimed a fan inside and went back to bed. It didn't go off again and was happy for the rest of the family visit (still with the door open and the fan pointing inside).

 

Now the family have left time to investigate.

 

There's a little baby fan on the variac brush (along with a thermal switch which is probably what killed the output), it was not rotating (seized solid). There was a replacement 12V fan in my "keep it for a rainy day" box, 30 mins later that's installed and going round.

 

Looking into the bowels of the beast revealed that the main ventilation fan also wasn't going round (220V 4" fan), this one wasn't seized, but was open circuit (burned out). A replacement was again rustled up from my magic box. Worked fine but was a LOT more noisy than the original (it lives in the corner of the lounge and was disturbing my enjoyment of the IPL). Bunged a 1uF 250V AC motor run capacitor in series which dropped the fan voltage down to about 120V, it's still moving air but is much quieter.

 

So we are back online, I'm a bit miffed that the fans failed after less then 2 years (cheap Chinese) but the replacements are better quality so with luck that's something else to not go wrong.

 

Next job is to add a thermostat to the main fan so it only runs when the box is getting warm, one of these is on order https://www.aliexpress.com/item/W3001-W3002-W3230-LED-Digital-Thermostat-Temperature-Controller-AC-110V-220V-DC12V-24V-Thermoregulator-Heating-Cooling/33004698151.html the W3001 220V version.

 

HTB1DfE5Rr2pK1RjSZFsq6yNlXXao.jpg

So the fan can run at full speed only when needed.

 

 

 

 

 

 

I know making the fan temp. controlled is not a big job, (I did this with the fans from the power supply from my CCTV). What I like from the CBC AVR, is that the fans (It has no door what is easy to open as the VEG) there are more, but I have no idea how many, are even speed controlled. At night I hear them hardly never running (supply voltage is also usual OK when it is cooler) at day time they only run when the load is high together with a low supply voltage.

 

Global told me they have loads of problems with the VEG AVR's

 

Arjen

  • Like 1

Share this post


Link to post
Share on other sites
8 minutes ago, Arjen said:

I know making the fan temp. controlled is not a big job, (I did this with the fans from the power supply from my CCTV). What I like from the CBC AVR, is that the fans (It has no door what is easy to open as the VEG) there are more, but I have no idea how many, are even speed controlled. At night I hear them hardly never running (supply voltage is also usual OK when it is cooler) at day time they only run when the load is high together with a low supply voltage.

 

Yeah, if I knew then what I know now I would have bought the CBC (at the time Global only had Lioa and VEG).

 

On the other hand the VEG is really easy to access for maintenance. If I could find some drawings for the beast I would be a happy bunny.

Share this post


Link to post
Share on other sites

Since the beast has demonstrated a propensity for going belly up in the middle of the night I have installed a bypass switch.

 

I had one of these in stock, it's actually intended as a generator transfer switch, but with a little lateral thinking it's become an AVR isolator and bypass.

 

https://www.aliexpress.com/item/2P-63A-MTS-Dual-power-Manual-transfer-switch-Circuit-breaker-MCB-50HZ-60HZ-400/32786129292.html

 

Drawings coming shortly.

 

Share this post


Link to post
Share on other sites

As promised, quick-and-dirty drawing

 

AVR bypass.jpg

 

All wires should be at least 10mm2, the neutral just goes past without connecting to the switches.

 

With the switches as shown the AVR is bypassed and isolated, check dead before touching anything.

 

Whilst the two breakers are interlocked so they cannot both be on together it is strongly advised to set them both to off whilst switching from normal (left breaker on) to bypass (right breaker on).

 

Share this post


Link to post
Share on other sites

Crossy, when you conduct testing on the VEG, how big a load do you use?  Or, after beating on it do you just punch it back in-line?

Share this post


Link to post
Share on other sites
20 hours ago, bankruatsteve said:

Crossy, when you conduct testing on the VEG, how big a load do you use?  Or, after beating on it do you just punch it back in-line?

 

A bit of both.

 

I have a 3kW "test load" (OK it's a UK kettle, bonus is I can have a cuppa whilst testing) which is enough to verify it's functioning and I can "adjust" the input voltage by turning on up to 14kW (60A or so) of water heaters (I don't own a variac).

 

The water heaters are on the supply side of the AVR, our load source impedance measures at about 0.5 ohms so 60A will give me a voltage drop of about 30V from whatever PEA are deigning to supply at the time (currently a nice 211V @ 15A load).

 

Otherwise bang it back in line and turn on the aircon.

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...