clean|power to the people Sign up for our Newsletter How to properly fuse a solar PV system NOTE: If you are unsure about this area, consult an electrician. Proper use of fuses and breakers are important to maintain safety. The first thing to know is that fuses and circuit breakers are primarily used to protect the system wiring from getting too hot and catching fire. Secondly, they also are used to protect devices from catching fire or from becoming more seriously damaged if there is a short circuit. A good example is a 12V lead acid battery. If a short develops in your AC/DC inverter for instance, a fuse between it and the battery will prevent a possible explosion of the battery and it will cut the circuit fast enough to prevent the wires from catching fire or getting dangerously hot. In this case, the battery, wires, and AC/DC inverter will be safely disabled by the fuse. Solar Panel fusing Commercially made solar panels over 50 watts have 10 gauge wires capable of handling up to 30 amps of current flow.

If you connect these panels in series, there will be no increase in current flow so fusing is not required for this string. This is not the case when you have panels connected in parallel, as when connected in parallel the system current is additive. air conditioning units for wide windowsFor instance if you have 4 panels each capable of up to 15 amps, then a short in one panel can draw all 60 amps towards that short-circuited panel. where is reset button on outside ac unitThis will cause the wires leading to that panel to far exceed 30 amps causing that wire-pair to potentially catch fire. air handling unit domesticIn the case of panels in parallel, a 30-amp fuse is required for each panel. If your panels are smaller than 50 watts, and use only 12 gauge wires, and 20 amp fuses are required.

Parallel/Combiner Box fusing In a parallel system a combiner box is used that holds the fuses/breakers to each panel, plus one or more “combined” fuse leading to the charge controller or grid tie inverter (see figure). When sizing this “combined” fuse/breaker, we must first determine the worst case current that will flow based on our specific panels. If we take the example 144-watt 12V panel from the introduction section, and look at the short circuit current (Isc), we see it is rated at 8.5 amps. This however can be exceeded if the actual installed situation does not match the “standard” test conditions used for solar panel factory ratings. The industry rule is to increase Isc by 25% to cover this possibility, so it now is 10.625 amps in our example. The National Electrical Code (NEC) also requires that a 25% factor be added if the load is continuous, so the number grows again to 13.28 amps per panel. If there are 4 panels in this parallel set, then the combined current can theoretically be as high as 53.125 amps.

The chart below shows the ampacity for wires in a conduit per the NEC. Note that some wires of the same gauge can handle more amps and higher temperatures. An 8 AWG USE-2 wire set (minimum) from the combiner box to the charge controller in our example will suffice, since it can handle 55 amps. A 60-amp fuse or breaker should be used in this case to protect this wire set. This also aligns with the maximum capacity of the charge controller selected. Charge controller to Battery Fuse/Breaker With a Pulse Width Modulated (PWN) charge controller, the worst-case amps flowing to and from the controller are the same, so the fuse and wire size can match. MPPT charge controllers, on the other hand, are able to both lower the voltage and increase the current flowing between the controller and the battery bank, so the exact size wire and fuse size must be recalculated or obtained from the charge controller manual. As an example, Blue Sky recommends a 60-amp fuse/breaker for their Solar Boost 50 (amp) charge controller between the unit and the battery bank.

Again, select a wire that is rated appropriately. Battery Fuse/Breaker to Inverter The wiring and fusing from the battery to an AC/DC inverter is of critical importance because this is where the most current will likely flow. Similar to the charge controller case, the recommended wire and fusing should be obtained from the inverter manual. It is very likely the invert already has a built in fuse/breaker on the input as well as the output (AC) side of the unit. A typical 1500-watt 12V pure sign wave inverter draws up to 125 amps continuously, a number that increases to 156 amps once we factor in the NEC continuous-use 25% adder. For USE-2 wires, 1/0 AWG is required in this case. For a hobbyist, welding cable is generally used with these general limits: #4 AWG 150 amps #2 AWG 200 amps #1 AWG 250 amps 1/0 AWG 300 amps 2/0 AWG 400 amps Final Note: This article was just an introduction. There are important related aspects such as cable length and fuse/breaker types that need to be studied before a design is finalized.

There are various free fuse and wire size calculators online that you should use in completing your solar PV system. If your take your time and use the right combination of rated parts, then the system should work well and you’ll sleep better knowing you engineered it to be safe and reliable. It looks like you're new here. If you want to get involved, click one of these buttons! Volkswagen Passat Fuse and Electrical Problems /It's a garage door opener that replaces the blank switch plate in the center stack. I don't have one (heh, I don't even have a garage!) but it looks pretty nice. Hi, Have a 2000 1.8l turbo Passat. There seems to be an interminttent fault. Indicators, wipers, headlights seem to drop out. Checked the fuses and seem to be no problems. Iknow we have an aircon problem, the bearings are just about had it so need to get serviced, however we are driving with the aircon off so should not be a problem. Sign In or Register to comment.1. Are you purchasing a Progressive Dynamics product on the internet?

Before you buy, ask the seller about their warranty procedures. Does the retailer provide a "working" customer service or service department phone number? Does the Progressive Dynamics product that you are buying have a valid serial number? Some online retailers are selling Progressive Dynamics' products without a valid serial number...We must have a valid serial number for all warranty service work. A valid serial number allows your warranty service topics to be handled smoothly and with ease. Call 269-781-4241, extension 145; 2. Why do Recreational Vehicles need Converter/Chargers? Remote camping in a modern recreational vehicle requires an electric power source (i.e. a 12-volt battery system). The power converter recharges the battery and supplies 12-volt power for the lights and appliances when 120–volt AC power is available. Most RV Manufacturers now specify Electronic Power Converter/Chargers. 3. What is an Electronic Converter/Charger? Electronic type converter/chargers were first developed for the military and aerospace programs to meet stringent requirements for reliability and small size.

As the cost of components decreased and reliability was increased even further, electronic converter/power supplies became the standard for the computer industry. Electronic converter/chargers had the advantage of being smaller, lighter and they provided the ripple free output voltages these sensitive electronic circuits required. In the early 1990’s, the component cost reductions and continued increases in component reliability had reached a point where it was economically feasible to design an electronic power converter for the RV industry. Progressive Dynamics introduced our first electronic converter in 1993 and since then, we have produced over 400,000 units. Our field experience and constant improvements have made our units the most reliable on the market today. 4. How do Electronic Converter/Chargers Operate? Electronic converter/chargers first convert the 120 VAC 60 Hz from the outlet to 120 VDC after it passes through Diode Rectifier #1, the Capacitor then filters the ripple voltage.

This 120 VDC voltage is then fed to an Electronic Switching Circuit that converts it to back to AC and increases the frequency from the original 60 Hz to 3,500 HZ. This high frequency AC voltage is now fed to a step-down transformer where the output voltage reduced to approximately 13.6 volts AC and Diode Rectifier #2 converts the AC to 13.6 Volts DC and the Capacitor filters out the ripple. 5. What is the maximum rate my Converter/Charger will re-charge my battery? The 9200 Series and 9100 Series electronic Converter/Chargers can charge the battery at their maximum current output rating, provided there are no other 12-volt systems operating and if the battery is discharged enough to accept this charge rate. Progressive Dynamics presently manufacturers six different models of the 9100 series and four models of the 9200 series power converters as shown in the chart below. The last two digits of the part number indicate its maxim current charging capability in amps. Maximum Output & Charging Rate

6. Does my Converter/Charger completely shut-off when the battery reaches full charge? When the battery reaches full charge, the charging current of the converter drops down to between 20 and 25 milliamps. Batteries will self-discharge themselves at this low rate even when no other 12-volt current loads are present. The converter senses this current loss and automatically replaces this lost current to maintain full battery charge. 7. Why doesn’t the fan on my converter run all of the time? The fan provided on Progressive Dynamics 9200 and 9100 series converters is an intelligent fan and uses an electronic temperature sensing system that operates the fan only as much as required usually under high current drain applications. This means that the fan typically will not operate at night when the RV owner has turned off most 12- volt lights and appliances and is trying to sleep. 8. Does my converter have short circuit protection? Yes, the 9200 and 9100 series of converters all incorporate a sophisticated electronic current limiting circuit that automatically shuts the converter down very rapidly in the event of a short or current overload condition, without blowing the fuses.

This protective circuit will automatically reset itself once the short or overload condition is eliminated. 9. What is the term of the converter warranty? The Progressive Dynamics new converter warranty is 2-years and is determined by the date of purchase of the RV. 10. What are the fuses on the front of the converter designed to do? These fuses protect the converter from damage in the event the battery is connected to the RV in reverse. A reverse battery hook-up is the only thing that will blow these fuses. Before replacing a converter suspected of being inoperative always, check these fuses first! These are standard automotive type 30 amp fuses. 11. How long will it take to re-charge my RV battery? Battery recharge time is controlled by many factors, such as battery size, converter output rating the number of 12-volt lights and appliances that are “ON” during the re-charge cycle and how far the battery has been discharged. In our testing a 125-AH (Amp Hour) battery was fully discharged to 10.5-volts and then connected to a PD9160 (60-Amp) Converter/Charger set to our standard output voltage of 13.6-volts.