Poles Apart
Am I referring to the vast range of poles available for window cleaning? in short no, discussing water fed poles, I will leave to those in the know to debate.
I want to discuss polarity sensitive electrical devices, in particular, controllers. I will touch on the difference between AC and DC, In other words, Direct and Alternating electrical current.
I want to look at the levels of protection built into you controller to stop it getting blown up and ways in which you can avoid miss wiring the control.
OK, Here we go the technical bit.
What then is the difference between DC (direct current) and AC (alternating current)?
A short history lesson most people know that Thomas Edison is the man credited with marketing Direct current power to the masses, However, what is less known is that his associate Nikola Tesla (https://en.wikipedia.org/wiki/Nikola_Tesla).
Tesla disagreed with the principle of large-scale DC as it requires every property to have its own generation plant. Tesler proposed AC was much more efficient as large stand-alone generation facilities could be built and the power could be transferred over long distances easily. Tesler, in fact, is responsible for the way power is generated and transferred to this day.
Batteries, Fuel cells and solar cells all produce something called direct current (DC). The positive and negative terminals of a battery are always, respectively, positive and negative. Current always flows in the same direction between those two terminals. On the other hand, the power that comes from a power plant is called alternating current (AC). The direction of the current reverses, or alternates, 60 times per second (in the U.S.) or 50 times per second (in Europe, for example). The power that is available at a wall socket in the
United States is 120-volt, 60-cycle AC power.
The term positive terminal describes which of the two connection terminals on direct current (DC) equipment supplies or is meant to receive a positive electrical charge. DC power supplies always feature a positive to negative electron and always have a negative and positive terminal. Most DC appliances or machines also have a positive and negative terminal which should always be connected to terminals of same orientation on the power supply. Failure to do so can cause severe damage to the equipment and power supply. This positive/negative relationship is commonly known as the polarity of a supply or device.
Any source of direct current electrical power flows from a positive source to a negative source. This applies to the DC side of rectified power supplies, batteries, and Solar panel outputs. Each of these DC power sources features a positive terminal and a negative terminal. The permanent relationship between positive and negative sides of DC power supplies is referred to as the polarity of the supply.
The universal colour code and symbol for a positive terminal is RED and a plus (+) sign. The colour code and symbol for a negative terminal is BLACK and a minus (-) sign. The polarity relationship, colour codes, and symbols for positive and negative terminals are also used on the devices powered by DC power supplies. The connection terminals on DC power supplies and devices will always be marked with one or both of these identifiers. When connecting DC devices to a power supply, it is crucial to observe the correct polarity. In other words, the positive terminals on the supply and device should be connected to each other with the same applying to the negative terminals.
In effect, the current can only travel in one direction around the circuit. Think of it as a one-way valve if you try to force the current the wrong way through the valve it will break and fail.
How is the Spring range protected against Reverse polarity?
As you can see from above-reversed polarity in a DC device is a problem, As a manufacturer we look to minimize any damage from a miss-wire (connecting the cables to the wrong terminals) We do this in a number of ways
The Controls are supplied with 1mm Tri cable rated to 18amps. The control itself is rated to 10 amps. Plus
1. Reverse polarity diode
2. Supply and recommendation to fit a fuse
3. Over current protection
1. We fit a Reverse polarity diode to the power supply circuit on the PCB. The diode is fitted so that in the event of a miss-wire (reverse polarity) it will blow preventing Current passing through the processor and drive chips and causing terminal damage. In this way, we are able to protect the sensitive parts of the control and effect a repair.
It is possible to fit a larger diode to offer higher levels of protection. However, the larger diode would generate more heat and make the unit less efficient. To counter this increased heat would require us to make a number of changes on the PCB. The result would be a larger unit which may also increase the cost of the unit.
We look to incorporate cleaners feedback into production We are aware that additional reverse polarity protection would be useful.
In honesty, we likely see a handful of controls come back to us having been miss wired. This does, of course, represent down time for the cleaner concerned for what may have been an innocent mistake. As such we are always reviewing the control and considering commercially sensible additions and development.
2. A fuse(s) is needed in any electrical system (AC or DC). These protection devices react to the amount of heat being produced by electricity passing through wires and/or components. They are used so as to protect wires and components from the extreme heat produced should there be an electrical overload or short circuit.
When a short or overload occurs, the amps being drawn spike and this increases the heat produced in the wiring and components. When this occurs, a fuse or circuit breaker reacts almost instantly to stop the flow of electricity in the circuit and thereby stopping heat production.
Without PROPERLY-SIZED FUSES, this quick break in the circuit would not be possible, and damage to components and even FIRE could result.
If you are having a problem with fuses "blowing" please know that these devices are doing their job! It is important that you NOT replace a fuse or breaker with a higher-rated one. Check the circuit for shorts or overloads.
Fitting a fuse even in the event of reverse polarity will provide additional protection even as the current passes the wrong way around the circuit with the fuse now on the output part of the circuit it will still blow preventing further damage to the processor and pump drive stage as described above. The circuit is broken and current is no longer able to flow.
3. For additional protection, we have added to the control an overcurrent circuit. This is a uniquely engineered device to be found only on Spring manufactured controllers. If the unit sees,s a sudden spike in current it shuts down the pump stopping the current draw from the battery by doing so the control is able to prevent very high current passing across it causing damage.
So what steps can be taken to avoid Miss wiring the controller.
As outlined above all electrical devices have a common colour coding to make it universal
RED or Brown are Positive
Black or Blue are Negative
Positive is always represented by the + (plus) symbol while Negative is represented by – (minus)
So when connecting Black cables will run to the Negative ( - ) terminal with Red cables to the Positive ( + ) terminal.
The cables on you controller use the International colour coding. Following this coding will ensure you can not miss wire the controller.
The controls are supplied with Bullet connectors as are the additional cable runs Please do not cut these off as it makes a poor connection
You could remove the Fuse prior to disconnecting the battery for charging only refitting it once you have checked the polarity is correct. After a while, this becomes a good
habit making miss wire much less likely.
Marking the cables with a tape of ties can also ensure correct polarity is followed.
As a manufacturer we recognize that on occasions mistakes happen so we engineer in a range of protection features to your controller. In the event of a miss-wire, the diode means the main circuits and processor of the control are protected and the diode can be repaired quickly and easily with the minimum of fuss.
We are committed to developing the controllers so they continue to be the best in the market as such we are researching developments that make the control easy to use and represent good value to the cleaner using the control day in day out.
I have briefly covered AC and DC, Polarity and standard Colour coding and marking for electrical devices. If the a mistake happens no worry returns the control to us or contact us for advice and if needed repair.
Good habits and taken a couple seconds to check your polarity is correctly connected will protect your investment and ensure you keep earning.