Let me start by saying that the safest way of connecting a portable generator set or any other power source to a house wiring is via a transfer system. The question of course is what to do if you don’t have one and a power outage caught you off guard? Fortunately, there are still some ways of energizing your house without a transfer switch, especially […] read more
Electricity for the home can be generated in a number of ways depending on the energy source. Below we will review your main options and power generator types. ENGINE GENERATOR SET The most common type of backup power source for the home is a set consisting of an electric generator and an engine, also known as genset. It contains […] read more
When you are choosing a portable generator for your home, besides power and cost, a key thing to consider is how you are going to fuel it. Remember, during a long-term outage, with a typical use you would need to refill your generator daily. Most inexpensive portable generators are fueled by gasoline. This is fine […] read more
In my previous post I described the wiring of the inlet for easy connection of a backup power. Here is a list of the parts in my battery backup system. MIDLITE 4642-W recessed power inlet with NEMA 5-15P plug (see image to the right). It comes with a narrow box, so that a regular extension cord […] read more
This is my battery backup project. I have a natural gas steam boiler that I want to be able to operate and produce heat in case of a power outage in winter. The boiler has an electronic ignition. There is also an automatic water feeder. I am not aware of any other electrical loads (I […] read more
If EPA will impose the new proposed standard for ground-level ozone, it may become the costliest U.S. regulation. The new pending standard would require states to reduce ozone level from the current 75 parts per billion to 60 ppb. According to an analysis conducted by NERA Economic Consulting, this would cost our economy about $270 billion annually! And there is no […] read more
This single-phase three-pole 4-prong 120/240V 20A locking socket is found in some low-power (typically under 4,000W) portable generators. Its pinout is similar to that of L14-30 except the notch in the ground hole is reversed. If you follow UL and NEC® 2014 80% loading guidelines, you can draw from this outlet up to 240x20x0.8= 3,840 […] read more
This single-phase two-pole twist-lock 120 volts 30 amps receptacle is common for small and mid-sized generators. If you load it to 80% of its rated current as recommended, you can draw up to 120x30x0.8= 2,880 volt-amp. The mating 3-prong plug part number is NEMA L5-30P. It has to be used with UL-listed cord containing three […] read more
This 3-pole 4-wire 50-amp straight blade style socket is common for most high-power (10kW and greater) portable generators. It provides 120/240V and is rated to 12.5 kVA maximum. In reality, if you follow NEC® and UL 80% derating guidelines, you can get up to 240x50x0.8= 9,600 volt-amps assuming you balanced the loads on X and Y. […] read more
TT-30R (also known as RV 30) is a standard outlet for travel trailers- this is what TT in the part number stands for. It is common in most caravan parks and recreational vehicles in North America. The maximum power rating of this receptacle is 125×30= 3750 VA. Practically, with 20% safety margin and because a […] read more
This twist-lock 30-amp part is probably the most common type of single-phase three-pole outlets found in most portable generators over 4,000 watt. Theoretically, its maximum rating is 250Vx30A= 7,500 VA. In reality, the generator normally provides only 240V rather than 250 (some manufacturers use color coding to indicate their connector’s voltage rating). In addition, UL and NEC® 2023 […] read more
When you do a web search for generator sizing, you will find plenty guides and online calculators. Most of them provide a list of typical wattages for common appliances. Unfortunately, their numbers may be inaccurate even when they come from major manufacturers. To demonstrate this, let me consider as an example the power consumption of a refrigerator. The chart below […] read more