POWER = MATH

When it comes to power and how much is required to operate your van, it all comes down to simple mathematics. In this section, we tried to simplify how to grossly calculate how much power you need to operate your tools and equipment, either you use a generator, use your van's engine or plug in at your clients.

 

UNDERSTANDING ELECTRICITY

The following water analogy is pretty common, not perfect, but it will give you a good idea of how electricity works:

Amperes (current)

Shortened to Amps, or the letter A, or the letter I in an equation.

Electricity consists of the flow of electrons through a conductor such as an electric wire - think of electricity as the flow/volume of water through a pipe. We measure the flow of electricity as an electric current, and electric current is measured in Amps. The bigger the current, the more electricity is flowing.

Voltage (pressure)

Shortened to Volts, or the letter V, and also the letter V in an equation.

Electrical pressure is called Voltage. Volts are what makes the current flow in the first place, it's like a water pump that propels water through a pipe. It creates pressure in the pipe, causing the water to flow. Increasing the Voltage will make more current flow.

In North America, the domestic supply is typically 110V.

Wattage (power)

Shortened to Watts, or the letter W, and also the letter W in an equation.

Electrical power is measured in Watts, i.e. how much energy is released per second.

In some cases, you'll see that some equipments specify the "starting" Watts and the "running" Watts. This is easily explained by the fact that some equipments need a surge of power to start, then regularize to a lower Wattage.

Formula

When reading specifications for your tools and equipment, some manufacturers will only give one or some of the parameters. In any case, here is the formula to help you figure out the possible missing data:

Volts (V) x Amps (I) = Watts (W)


HOW MUCH POWER DO YOU NEED?

Below is a list of  the most common equipment aboard a grooming van. It might not be exactly what you have, but it will give you a good idea. It is impossible to list all brands, so many of these numbers are the industry average.

 
EQUIPMENTDESCRIPTIONVOLTSAMPSWATTS
AIR CONDITIONING 15,000 BTU 120V Average 16A 3,500W for start up
1,500 to 1,950W running
FANS Regular RV ceiling vent 12V Depends on speed 1.9 to 3A 24 to 36W
DRYER K-9 II
Chris Christensen Kool Dry
XPOWER B-8 Elite Pro
120V
120V
120V
18.5A
4 to 9.7A running - 11.7A start up
12A
2,220W
1,350W start up - 1,025W running
1,440W
CLIPPER Andis
Wahl
Oster
120V
120V
120V
0.2A
0.2A
0.4A
25W
25W
45W
CLIPPERVAC Mini ClipperVac 120V 7A 840W
VACUUM 8 to 10 gallons ShopVac 120V 8.5 to 11.5A 1,020 to 1,375W
WATER PUMP Average RV water pump 12V 9A 108W
WATER HEATER If you use the electric back-up
instead of propane
120V 12A 1,440W
REFRIGERATOR Average RV 3 cu. ft. mini-fridge 120V 5 to 8A 350 to 600W
MICRO-WAVE OVEN 450 Watt
650 Watt
120V
120V
7.5A
10.5A
900W
1,300W
LIGHTING Fluorescent
LED
120V
12V
About 0.3A per tube
About 0.6A per meter
About 32W per tube
About 7.2W per meter
RADIO Example for a satellite radio
and 2 speakers
12V 5 to 10A 50 to 200W
BATTERIES/INVERTER Example for nightly top up of
2 x Outback 2000 batteries
120V 8A 960W
MISCELLANEOUS Phone charger
DVD player
120V
120V
0.03A
1 to 1.5A
4W
120 to 180W
 

IF YOU USE A GENERATOR (diesel or gas)

Most onboard generators in grooming vans are powerful enough to run several items concurrently - they usually allow 4,000 to 8,000W, so plenty of power to run many pieces of equipment concurrently.

You should still add the Wattage of all the equipment you might run a the same time to make sure your generator can take the load.

 

IF YOU USE THE VAN'S ENGINE/ALTERNATOR

This set-up is hard for us to give you numbers, because many variables can affect them:

  • Single or double alternator system?

  • Fast idle switch?

  • How many batteries?

  • And many other elements which can change the power you have access to.

Although it might sound like using this set-up is very powerful, well, it's not. The most you can get is an average of 20 Amps/2,400W.

You are not getting the power from the engine with this set-up, but rather the engine is used to charge a battery bank, therefore, the amount of energy you have access to is very limited and rapidly depleted. You can always idle your van's engine, but even then, the batteries can't be recharged fast enough for you to have access to ample reliable power like with a generator.

 

IF YOU PLUG IN AT YOUR CLIENTS

Most modern residential circuits in North America are 15 or 20 Amps (the breaker will be labeled either 15 or 20), so we're looking at a max load of either:

20A Breaker = 2,400W

120V x 20A = 2,400 Watts

15A Breaker = 1,800W

120V x 15A = 1,800 Watts

IMPORTANT: 1,800W or 2,400W before the breaker trips if the breaker is relatively new, older breakers will trip over a lower load.

Which means that whatever pieces of equipment that you want to run concurrently, cannot exceed a total of 1,800 or 2,400 Watts, depending on what is available at your client. A few more important notes to consider with this set-up:

  • If you run the air conditioning, there are VERY few other equipments that you can use at the same time, if any (maybe the clipper, lights, radio). You might not be able to run the air conditioning at all if your client only has a 15A breaker.

  • You can't run the air conditioning and a dryer at the same time (1,500W + 2,220W = 3,720W and the most you can have is 2,400W if your client has a 20A breaker).

  • The plug your client will allow you to use on site doesn't mean it is a dedicated circuit for you and your equipment. The client may already have household items plugged on that circuit, therefore leaving you even less than 1,800 or 2,400W to use.

 

Please visit our TYPES OF CONVERSIONS page for more details on each set-up.