Advanced Marine Electrics and Electronics Troubleshooting A Manual for Boatowners and Marine Technicians

72 electrical systems troubleshooting

Selling for around $150, the WattsUp? is

affordable, and costs far less than high-end,

scope-type power analyzers, such as the Fluke

model 434, which run between $4,000 and

$4,500. (Unless your work involves large

marina or shipyard power systems and mega-

yacht-sized vessels, this cost would be hard to

justify, since power analysis is not something

that needs to be done all that frequently.)

Unfortunately, the WattsUp? works only with

120 V, 60 Hz appliances, so its usefulness is

essentially limited to North America.

The unit is simple to operate, requiring

only that you plug it in between the appliance

in question and any 15 amp receptacle and let

it run.

If the appliance is hard-wired into the

boat’s AC system (which is the case with many

battery chargers, for example), simply make

up a 15 amp, three-prong plug assembly with

an insulated three-terminal strip to temporar-

ily disconnect from the boat and connect to

the appliance feed cable. Using this adapter,

WattsUp?, Electronic Education Devices, http://www.doubleed.com (available through Professional

Equipment, http://www.professionalequipment.com)

PORTABLE POWER ANALYZER

plug the WattsUp? into a conventional wall

socket and attach the three-wire adapter to the

appliance via ring terminals at its power input

bus and the three-prong plug at the other end

of this short jumper (about 12 to 18 inches

works fine) plugged into the WattsUp?.

Warning: Turn off all power to the appli-

ance you are connecting this adapter to until

all the terminations are made. Shock hazard

exists if you inadvertently grab one of the

live wires that you’ve temporarily exposed.

Comparing Power Consumption

I recently used the WattsUp? to compare two

6,000 Btu air conditioners; the newer one was

an Energy Star qualified unit, and the other

unit was about five years older. I’ve summa-

rized my results in Table 6-1.

These differences may not seem like much,

but on a boat equipped with multiple units

cycling all the time, the cumulative difference

over time can be considerable.

Average Draw Peak Draw Power Factor

(compressor (at compressor Power Factor (compressor

running; watts) start-up; watts) (fan only) running)

Older unit 800 1,901 1.0 0.89

Newer, Energy 560 1,724 1.0 0.98

Star unit

Power Consumption of Two 6,000 Btu Air Conditioners

TABLE

6-1