Determining What Size Generator You Need
Choosing the right size generator to suit your needs is the most important part of your decision. Underestimating your power needs can not only slow or stop your operation – it can damage important equipment.
We’ve put together a handy information sheet to walk you through all of the details, which we recommend you download and read. But in the meantime, here are a few of the critical factors that go into your decision.
Different pieces of equipment have different tolerances for voltage dip, and the starting load of an electric motor can be as much as six times its running load.
Since that starting load can affect your generator’s regulator system by reducing the available voltage, you need a generator large enough to handle the maximum allowable voltage drop. You’ll need to consult the manufacturer’s spec sheet for your equipment to determine what the allowable drop in input voltage is.
Generators have a nominal frequency (60Hz in North America). But, extremely heavy loads, especially on start up, can reduce engine speed, affecting that frequency. The maximum transient drop in speed and frequency of what the system can handle both need to be taken into account.
Any combustion engine requires a certain amount of air to function properly. Your altitude, humidity, and temperature range will all affect how well (or poorly) your generator operates.
Generator manufacturers provide guidelines for what percentage of power reduction you can expect when ambient conditions exceed the nominal rating.
Generators come in either prime or standby. Your commercial application will determine your backup power needs: whether you require continuous operation from generator power, or if you need only temporary coverage during main power interruption.