Wednesday, May 25, 2016

Surge Protectors and Suppressors

All Appliance Repairs in Port Elizabeth

Electrical Filter is the layman's term for suppressors and surge protectors. Most good appliances has Surge protection unit build into them.

Microwave Oven Surge PCB

All Appliances in South Africa has been taking beatings and major abused from our National Electrical supplier with their inconsistent ("Loadshedding") power supply schedules.
Although the "loadshedding" has become less, we still have daily uncontrollable electrical spikes.

In South Africa and most other countries receive AC power (alternating current) from their national grid supplier. Like the names says "Alternating Current" - it means the power supply is alternating (like waves in the ocean) The voltage goes Up and Down. Sometimes it will spike at 300+Volts and then down to 180 Volts. In the RSA we use 220 volts, the USA and Europe use 110 Volts.

Surge spikes (also called transients) are measured in units of 10 -6 Second. Transients that cause havoc inside appliances normally are in the several hundreds range and a lightning strike goes into the Thousands.

Electrical Surges and Spikes are a fact of life and they will always be with us

This is the reason why all appliances need surge protectors and suppressors

TVSS (transient voltage surge suppressors)

These little devices  or commonly called SPD (surge protection devices) come in many different and sizes but for this simplicity I will only cover the ones you find and use in everyday Household appliances.
Washing Machine Electrical Line Filter that has exploded

Surge Diverter

The surge diverter relays (or blocks) a electrical spike above a certain voltage down to the ground. This normally creates a electrical short in your system but I will discuss this effect more in detail in another post.

Transient Voltage Suppressor
Diott

TVS's  is commonly used in Household All Appliances and it react to momentary voltage spike . Commonly known as voltage Zener suppress diott.


Metal-Oxide Varistors
Hoover PCB With MOV

MOV is more found in electronic circuit boards and TV, sounds systems and top range microwaves. The Mov's are fast and they respond to a voltage surge much quicker than any of his other suppressor buddy,s. Their main function is to protect the other electronic components  from a "over-voltage"

One can just keep on going about the many different types of suppressor and diott that is out there - like you also get a unit that is filled with gas.

OK, ok! I will stop now!

I do not want to risk losing you because of overexpose to boredom. My fascination might be toxic to your entertainment system.
Getting back to the reason why I am telling you about these little appliances (suppressors) is because of safety and also to tell you it doesn't always pay to be a cheapskate.

MOV has been Documented to Burn

Some electronic manufactures tend to be cheap when designing voltage protectors and the installation thereof.
Defy Dishwasher PCB overheated causing panel to meld

While the overvoltage might not be enough to blow the fuse or destroy the MOV, it does cause the PCB unit (printed circuit board) to overheat. The overheated MOV will eventually then start the fire.

The are many factors that separate the good manufacture from the not-so-good ones but here are a couple easy noticeable ones
  • Silicone wire is used or flame retardant materials (Defy appl use it in most of their units)
  • The surge PCB is installed in a remote area inside the appliance so that even if it catches fire it will not cause the whole appliance to burn
  • As a habit one should always try to fit and use surge protection units but there are so many dummy units out in the market place. It is very difficult to direct you from a distance what to look out for because on the outside they all look legit.
  • I would recommend is to find yourself a good electrical supplier (be careful for the national franchises because they buy in bulk from the east on "good deals") and also think twice next time when you buy cheap unbelievable deals. (they can make it so cheap because they schimp on necessary safety equipment). 
  • Always ask about the appliance backup service because after the supplier guarantee period has expired you could be stuck with an electrical item with no backup service. 

Hope this information has added some value to your time and should you need more leave a comment below or see you over at our facebook page    https://www.facebook.com/Appliancesa

www.pinepienaar. info







Mobile No: 083 52 52 522

Friday, May 13, 2016

Hoover Condenser Tumble Dryer model VHC 391

Tumble Dryer Repairs in Port Elizabeth

We recently had the honor to service a Hoover tumble dryer mode VHC 391. I can actually count on one hand the times we had this specific model in our workshop. This Dryer was build in the true Hoover Superior tradition and it has so many unique feature which will take forever to tell you about them.

The Condenser Dryer

Hoover Condenser Tumble Dryer modelVHC 391

Condenser Dryers keep the wetness/condensation inside the dryer and it has a unique drip-tray where the water accumulates. Just to explain what this means, in our part of world (Eastern Cape) if you use a normal tumble dryer the water evaporates into the air which is all fine on normal days
The snag comes in when you live in a small apartment or the machine is kept in a small laundry room. On a humid days combined with the evaporated water from the drier results that wetness moves into already dryer garments.

This dampness which you don't think is now on your garment and it will make your clothes start to smell moldy.  
Most of the time you don't even pick it up straight away, its only when your body starts heating up from around about 10 - 11 in the mornings. This also the time when most people tend to blame their Washing Machines or detergent.

Hoover Condenser Tumble Dryer model VHC 391 front door switch and inner drum expouse
We can go more into how important it is to keep the environment around your tumble dryer clean at all times because when taking dried out garments out of the dryer it will suck-in moister from the immediate surrounding straightaway. If the kitchen dustbin or smelly dirty garments are lying nearby the newly dried garment it will get some of those smells in newly dryed garments. I will discuss this drying process more in a another post

The actual reason why I did this post is to show (pictures) you the reason why it is so important to have your tumble dryer serviced or cleaned regularly. Autumn is here and winter is the time when you use tumble dryers the most and you don,t need a breakdown when you need it the most.

Hoover Condenser Tumble Dryer model VHC 391 Front covered with fluff

Fluff

Fluff is the number one reason why tumble drier fail
  • Fluff blocks the flow of hot-air inside the tumble drier which results that instead of the Hot air move through the garments and to the outside, it now lingers inside the dryer unit causing the motor and timer (programer) to overheat.
  • When the tumble-dryer airflow are restricted it takes much longer to dry Garments resulting in using more electricity.

Hoover Condenser Tumble Dryer model VHC 391 Motor is completely covered with fluff
When the motor is covered with fluff the operating temperature rises by two or more degrees causing the motor fail.

One of the most common symptom of a failing motor is that it does not startup (turn) on its own. You hear this humming noise and the drum heats up but nothing is turning.

When you swing the motor with your hand it works fine again - THe reason for this is that the start winding is damaged but the run-windings are still fine.
Hoover Condenser Tumble Dryer model VHC 391 Motor
Motor windings

Windings are the copper wire coils around the motor armature - in which the electric current flows. The electricity in these copper coils creates a north and south pole (like in a magnet). Once the motor overheats the insulation between the copper coils melt and it starts to lose their poles.

In Tumble Dryer and Washing Machine motors there are more than one set of windings. The following sets are found;
  • Left Start winding
  • Right start winding
  • Left run
  • Right run
Most of the time it is only one set of windings that get damage resulting that the Appliance still has some limited functions


Hoover Condenser Tumble Dryer model VHC 391 Before and After Servicing

Sadly I must report Hoover has gone by the wayside and backup service are limited. I can't help but wonder how such a super manufacture of legendary vacuum cleaners and household appliance just faded away. 

If you have more information about this please share it with us
WWW.PINEPIENAAR.INFO
 (Mobile+27835252522)

Ps. The only cost effective condenser tumble dryer is the same class as this hoover model are the Whirlpool which also has a very big inner drum.