JD
Well-Known Member
Sorry bishop, I know the topic is serious, but this phrase made me spit my coffee out!
Will this DMX dimmer pack control 8-10 PAR64 (1kW)?
- Thread starterstonehedge99
- Start date
Sorry bishop, I know the topic is serious, but this phrase made me spit my coffee out!
JChenault
Well-Known Member
Some good responses to this thread, but I thought that in the sense of “Teach a man to fish” it might be useful to explain how to answer these kinds of questions when you don’t have access to Control Booth.
First some very basic ( simplified) electrical knowledge. When you have a light bulb, you are passing electrons through a wire into the fixture. The force behind those electrons we call Voltage. The number of electrons we call Amperage. How bright the lamp is based on the Wattage of the lamp. All of these factors are interrelated by a formula ( W = V*A) IE The wattage of a device is the Voltage times the Amperage. This is sometimes called the “West VirginiA” formula.
Now for must applications, what you have to worry about is getting too many amps in your wires or devices. If you put too many amps through a wire, it will melt and cause a fire. In the old days the circuits in your house had a fuse. The power to your wall outlet went through the fuse and if there were too many amps in the circuit, the fuse would melt before the wire did. Today we have circuit breakers that trip the circuit ( IE interrupt the flow of electrons) when too many amps are flowing through it.
So let’s go through an exercise of “Can I fit 5 500 watt par cans on a shoebox dimmer ).
The first thing to do is figure out the amperage of each fixture you plan to use. We figure out the amperage by our formula ( W=V*A). Assuming 120 volts that would be “ 500 = 120 * A “ This gives a value for ‘A’ of 4.2 amps. ( Note – If you don’t have enough math to figure this out, please stop reading and do not try to figure this out yourself.)
If you are using a shoebox dimmer with four dimmers, one of the dimmers will have two fixtures plugged into it. That dimmer would have a total of 8.4 amps ( or 1000 watts) of load. Look at the spec for the dimmer and see what is the capacity of each dimmer . This may be expressed in amps, or in watts. If the value of each dimmer is 1000 watts, ( 9 amps) you can plug two fixtures into a dimmer.
But we are not done yet. Let’s assume that you want to run all of your par cans at full. This means that the dimmer pack will be running 5*4.2 =21 amps / 5*500 = 2500 watts. If you look at spec for the dimmer you are likely to see something like “ The maximum capacity of the dimmer pack is 15 amps’ What is going on here is that the power feeding the dimmer typically uses an Edison style plug that is rated for 15 amps. If you put more amperage through it, it will ultimately melt. Sometimes you see one of these shoebox dimmers with the ability to have two feeder cables. So if you have one with two plugs on it ( each plug feeding two dimmers) the dimmer would work for your application. If not, you need at least two dimmer packs. In either event you have two cables to plug into the wall.
But wait, we are still not done yet. At this point you need two sources of power to drive your fixtures, in shoebox dimmers this is typically a wall socket. In most buildings, you will have a single 20 amp circuit breaker controlling a number of wall outlets. If you have a standard duplex receptacle, you can be pretty certain that there is a single 20 amp breaker providing power to both of the receptacles. So if you plug both feeders from the dimmers into the same receptacle, and run your fixtures up, you will be pulling 21 amps over a 20 amp circuit breaker, and it will trip leaving you in the dark. You need to find two circuits that are controlled by different circuit breakers and use them to power your dimmer packs. ( and that do not have major loads on them as well). If you have access to the circuit breaker box, you can usually tell what receptacles are on what circuit breaker by the labels in the panel. If you don’t have access to the breaker box, it is probably a bad idea to try to do this since if you overload the breaker, you will not be able to reset it.
Ok - Now we are done.
First some very basic ( simplified) electrical knowledge. When you have a light bulb, you are passing electrons through a wire into the fixture. The force behind those electrons we call Voltage. The number of electrons we call Amperage. How bright the lamp is based on the Wattage of the lamp. All of these factors are interrelated by a formula ( W = V*A) IE The wattage of a device is the Voltage times the Amperage. This is sometimes called the “West VirginiA” formula.
Now for must applications, what you have to worry about is getting too many amps in your wires or devices. If you put too many amps through a wire, it will melt and cause a fire. In the old days the circuits in your house had a fuse. The power to your wall outlet went through the fuse and if there were too many amps in the circuit, the fuse would melt before the wire did. Today we have circuit breakers that trip the circuit ( IE interrupt the flow of electrons) when too many amps are flowing through it.
So let’s go through an exercise of “Can I fit 5 500 watt par cans on a shoebox dimmer ).
The first thing to do is figure out the amperage of each fixture you plan to use. We figure out the amperage by our formula ( W=V*A). Assuming 120 volts that would be “ 500 = 120 * A “ This gives a value for ‘A’ of 4.2 amps. ( Note – If you don’t have enough math to figure this out, please stop reading and do not try to figure this out yourself.)
If you are using a shoebox dimmer with four dimmers, one of the dimmers will have two fixtures plugged into it. That dimmer would have a total of 8.4 amps ( or 1000 watts) of load. Look at the spec for the dimmer and see what is the capacity of each dimmer . This may be expressed in amps, or in watts. If the value of each dimmer is 1000 watts, ( 9 amps) you can plug two fixtures into a dimmer.
But we are not done yet. Let’s assume that you want to run all of your par cans at full. This means that the dimmer pack will be running 5*4.2 =21 amps / 5*500 = 2500 watts. If you look at spec for the dimmer you are likely to see something like “ The maximum capacity of the dimmer pack is 15 amps’ What is going on here is that the power feeding the dimmer typically uses an Edison style plug that is rated for 15 amps. If you put more amperage through it, it will ultimately melt. Sometimes you see one of these shoebox dimmers with the ability to have two feeder cables. So if you have one with two plugs on it ( each plug feeding two dimmers) the dimmer would work for your application. If not, you need at least two dimmer packs. In either event you have two cables to plug into the wall.
But wait, we are still not done yet. At this point you need two sources of power to drive your fixtures, in shoebox dimmers this is typically a wall socket. In most buildings, you will have a single 20 amp circuit breaker controlling a number of wall outlets. If you have a standard duplex receptacle, you can be pretty certain that there is a single 20 amp breaker providing power to both of the receptacles. So if you plug both feeders from the dimmers into the same receptacle, and run your fixtures up, you will be pulling 21 amps over a 20 amp circuit breaker, and it will trip leaving you in the dark. You need to find two circuits that are controlled by different circuit breakers and use them to power your dimmer packs. ( and that do not have major loads on them as well). If you have access to the circuit breaker box, you can usually tell what receptacles are on what circuit breaker by the labels in the panel. If you don’t have access to the breaker box, it is probably a bad idea to try to do this since if you overload the breaker, you will not be able to reset it.
Ok - Now we are done.
