Compact Equipment

SEP 2018

Compact Equipment is a magazine dedicated to equipment owners and operators of small, nimble, tool-carrying construction, landscape and ag equipment — such as skid steers, mini excavators, compact tractors, generators compressors and beyond.

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Page 45 of 55

46 Compact Equipment SEPTEMBER 2018 (a.k.a. starting watts) and then add that number to the continuous pow- er (running watts) for all the other units. Here's an example: A circular saw takes 2,300 starting W but 1,200 W to run, and a hammer drill takes 3,000 W to start but only 1,000 W to operate. Conversely, your halogen work light takes 1,000 W to run. If you add up the items above, it will total 5,200 W (3,000 + 1,200 + 1,000), so you'll need a generator with a continuous power rating of at least a 5.2 kW (5,200 W). If you can't find the wattage amount, don't worry. All you need to know is the volts and amps of your equipment. To calculate the wattage, just mul- tiply volts times amps. So, your cir- cular saw, which operates on 110 V and consumes 20 amps, needs 2,200 W to run and requires a generator with a power rating of at least 2.2 kW (2,200 W). Just remember: Only equipment with electrical motors re- quire additional power at the begin- ning to start. Not understanding power require- ments can have consequences. Take wet stacking, for instance, which is a condition where gross dark liquid congeals in the generator's exhaust stacks. This occurs when unused die- sel fuel, accumulated moisture and carbon particles are allowed to gather in the exhaust of a gen set. This can happen for a number of reasons — a gen set sitting unused or not having fuel in your unit — but also running the generator at less than 60 percent of its rated output. "Make sure your generator fits the application, so it is not oversized or undersized," suggests Jim O'Brien, vice president and business line man- ager of power, pumps and light at At- las Copco. "Make sure it is not too big of an engine for the application." Sizing problems can be more sig- nificant with Tier 4 Final emissions regulations, which often require complex aftertreatment devices. For instance, the generator may shut down if over- or under-powered and begin a regeneration process in what's called a diesel particulate fil- ter (a through-the-wall flow device that traps and holds particulate mat- ter) before it can become operational again. "If you continue to do that, you can really hurt the machine," says Brian Northway, field service manager at Allmand. "Today, you re- ally have to know what your load is as opposed to before when you just threw any size load on and as long as it was bigger, you were fine." Alternative Technologies Did you know you can actually connect multiple generators togeth- er to increase the power capacity, control load management and ease maintenance for a group of genera- tors? It's called paralleling. By par- alleling multiple gen sets together and matching the load to the power need, it can even offer better fuel ef- ficiency. "It is something that's being used all over the world, and we're trying to implement it here in the U.S.," says Angel Nieto, product manager of power and light at Atlas Copco. The paralleling process involves the physical connection of two or more generators and the synchronization of their outputs, matching the wave- form of the output voltage of one unit with the voltage waveform of the other generator or generators. Factors include capacity, redundancy and compliance with electrical standards. "It allows you to have flexibil- ity on the power needs and the fuel consumption," says O'Brien. "It also saves runtime on the machine, and the resale value stays high."

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