Element Current Alerter or Open Circuit Element Alerter

If you know how to use one of these, you can diagnose the problem in about 10 minutes.

Tahnks a lot for the answer but the end user must be know which refrigerator has a problem and before the technical perseon perhaps they must transfer the goods to another box.

but the end user must be know which refrigerator has a problem

Ummmmmm....... the refrigerator that has the problem is the refrigerator that isn't cold. I just diagnosed your problem from half a world away.

Send me your address so I can send you my consultancy fee invoice! My minimum is $250.00 USD. Please have a money order ready! I take cash also, just no personal checks!

A good quality DMM or Digital Multi-Meter like one in the picture below in the hands of a trained technician is all you need!

Read the manual and have fun, just watch out for the AC voltage.... It BITES!

There are several voltage & current monitoring devices with programmable alarm contacts available in the market today.

If you want a simple circuit for monitoring each refrigerator heating element I would install a current monitoring and indicating device in series with each heating element on every machine that displays the DATA locally.

If this is a production line I would install monitoring devices that have both programmable alarm contacts and remote communication capability in Ethernet, MODBUS, DH485, or RS232 so that the alarms and DATA can be viewed by the operator at the control hub/room.

Although there are many good companies that offer these products I suggest you go to OMEGA Engineering and obtain their free technical application guides then review the guide that fits your particular application. www.omega.com

If for some reason you have trouble understanding the information then contact OMEGA Engineering for free technical application support on their offered products.

As I stated before there are many other reputable instrument & control vendors that offer the equipment you need.

Once you decide what is needed by referencing the free technical guide(s) you can then decide which particular product manufacturer you want to use.

Too late to edit, but you can probably use a 3000R resistor, and 240V neons for both indicators (but it would need a 25W resistor!).

The information is very useful but I need to learn what is the CT100:1 brand and model for order. Where can I buy and which product number can be order.

GA.

These would connect into his existing system well, I just don't know if they have the technical experience to install them!

I say they don't.

"If one or more element is a open circuit how can we identify?"

Thanks MacGyver, I hope they do, or figure it pretty quick, in the worst scenario the learning curve will cost $9.80

And the cost of a box full of "goods".

Besides, the wiring diagram on the back of each unit is in black and white, but the terminals are green and blue. ;>)

Since he says it is a refrigeration system, all one has to do is look at the evaps and you can see which are not defrosting, put a meter on each element and there you are. If the evaps are clearing the ice and frost in each defrost cyccle, who cares if all of the elements are working! -- JHF

Often you can't see which one is not defrosting until the ice is protruding from the coils, by then the element can be encased and it's damned hard to get to it.

Manually defrosting a coil is tedious, and it won't clear itself if there are other evaps. in the room.

If a coil freezes, its airflow will cease (I've seen them where the fan itself was encased in ice). If it is only one evap. in the room then you will soon know as the temp. rises, but many large freezers have multiple evap. units, so detection of a fault is not necessarily done quickly, and as many rooms have door switches to turn the airflow off when the door is open, then freezer staff are unlikely to be aware of lack of airflow from a coil.

There is also the possibility that these are humidifier rather than defrost elements.

Edit... I removed your OT vote as I don't consider your point OT at all.

Hello Spades, I'm a big fan of simplicity and your design will work wonderfully; but then I thought that an industrial operation that involves 40 freezers should render some profit, so they can afford an upgrade to their monitoring system. GA, I confess that my first thought was very similar to that of yours.

The circuit is useful. But what is the diode values and the indicator details? ie diode can bu use 1N4007 and etc if we give an order. The load is a heating elementand it works with a 240V ac and when it powered the current meter is shows 8 Amp. consumption on the line.

The diodes can be just about anything rated at 400 peak inverse volts and adequate forward current to manage the indicator lamp amps (2 amps would be quite adequate). They are not carrying full element current. 1N4007 would be fine as would the lower rated 1N4004.

The lamps can be anything from a low wattage incandescent (up to about 5 watts) to neon to LED.

If using LEDs, then use full wave 240v AC indicator packages.

The AC will be half wave through the indicators, but this will not cause any problems.

"The diodes prevent the indicators lighting incorrectly." Sorry if I'm being thick, but how?

If the diodes were not present and the element was open circuit, then both indicators would light when the contact is open.

This is incorrect as both indicators should be off at this point.

The power indicator should only light when the contact is closed, and the fail indicator should only light when the contact is open and the element is intact. Only half voltage would be applied to each indicator, but this is sufficient to light them, particularly if they are LED or neon.

The diodes being in opposition prevent the error by blocking both half cycles through the indicators when the contact is open and the element is faulty, but otherwise allow them to light at the correct times.

Oh yeah, thanks. I was being thick! . Been a long, hard week.

@kazimates, you say you have 40 indicators showing that the element is powered. You also say you have an Amp meter that indicate 8Amp, is this an Amp meter for every heater or is it 8 Amps for all. This is only 200 mA per heater and that add to 48 Watt per heater. I think you have an Amp meter for every heater already, that means that every heater is 2000 Watt heaters, so if the heater is powered and the amp meter reads 8 Amp the heater is working, if the Amp meter show nothing it means the heater is not drawing (allowing) current and that mean it is burnt out or technically called "Open circuit". I'm not sure what you mean by burned but if you refer to a short circuit, rest in peace because that will blow up something if you do not have a fuse on every circuit, if you have the fuse for the short circuit will be blown.