B&K 200.5 amplifier on 15 amp circuit

[gcmarshall]

just curious of anyone's experience with a B&K 200.5 (or similar model) amplifier on a 15 amp shared circuit. i have considered buying this model, but decided to call B&K just in case to ask some generic questions. i happened to ask about plugging it in and they strongly suggested a dedicated 20 amp circuit. well, my retailer said it would be fine on any old circuit. of course, i place much more faith in the manufacturer's recommendation, but am curious what your experiences are??? i live in finished construction, with no basement or crawl space, making it next to impossible to install a new 20 amp circuit.

anyone?

[Kevin P]

As long as the amp isn't sharing the circuit with power-hungry appliances (toaster, refrigerator, A/C, plasma TV etc.) it should be fine.

Most amps draw a few amps when powered up to charge their capacitors, then they draw little power until they're pushed hard, but unless you're running a 300x7 amp into 4 ohm speakers and keeping the volume cranked, you shouldn't have any problems running it on a 15 amp circuit.

[Dmantis]

Agreed,
the amp is a high current design and the best way to have it is with a 20 amp circuit deadicated along with the rest of the systems gear only on that circuit. 15 amp circuits are fine 2 as long as Krell isn't in your near future.

[Ralph P.]

Greetings,

I am running a Reference 200.7 Series 2 on a 15 amp circuit with no problem.

[Hoopofficial]

You shouldn't have any problems. The unit runs warm though. It heats my 15 x 18 AV room well. Nice bi-product in the winter. Not so good in the summer though! :W

[gcmarshall]

i received an e-mail from B&K indicating that damage to the B&K Reference 200.5 amplifier could occur is it is not on a dedicated 20 amp circuit.

[Glen B]

i received an e-mail from B&K indicating that damage to the B&K Reference 200.5 amplifier could occur is it is not on a dedicated 20 amp circuit.

A dedicated circuit of EITHER 15A or 20A maybe yes, but I don't see why specifically 20A ? All else being equal [circuit wire size] the only difference between a 15A and 20A circuit is the size of the breaker and unless the total power consumption of the amp is greater than 1,800W, the amp can't tell what size circuit its on. Even if the manufacturer specifies a 20A circuit because of inrush current, as long as the breaker can deliver that current without opening, again, the amp will not know what size circuit its on. :huh:

[MTAtech]

A dedicated circuit of EITHER 15A or 20A maybe yes, but I don't see why specifically 20A ? All else being equal [circuit wire size] the only difference between a 15A and 20A circuit is the size of the breaker and unless the total power consumption of the amp is greater than 1,800W, the amp can't tell what size circuit its on. Even if the manufacturer specifies a 20A circuit because of inrush current, as long as the breaker can deliver that current without opening, again, the amp will not know what size circuit its on. :huh:

The wire and breaker are the only differences between 15A and 20A lines but they are big differences.

What B&K is saying is that the amp may draw, at max, more than the limits of a 15A circuit. According to the B&K Ref 200.5 Manual the 200.5 consumes 130 watts @ no input; 1830 watts max and
17.5 Amps max current draw. That's above the limits of a 15A circuit. Now, you may never hit maximum draw but B&K would be amiss if they did not warn you of this fact.

Here is more detail:

From Newsday : To determine if a circuit has enough power or capacity, you need to do a little math. Circuit capacity, measured in watts, is determined by multiplying volts times amps. So if you have a 120-volt circuit controlled by a 15-amp breaker, you have circuit capacity of 1,800 watts (120 x 15 = 1,800). With a 120-volt circuit controlled by a 20-amp breaker, the capacity is 2,400 watts. To work the other way or determine the size of breaker you need for a circuit, use this equation: watts divided by volts = amps.

There are rules for wire usage, too. Those gauges are important. For standard 120-volt circuits, 14-gauge wire should be used on a 15-amp circuit, 12-gauge wire should be used on a 20-amp circuit, and 10-gauge wire is used on a 30- amp circuit. In most cases, if a circuit is going to be used for heavier appliances or power tools, a 20- or 30-amp circuit will be used. For lighting and smaller appliances, a 15- amp circuit is appropriate. For 240- volt circuits, a special four-strand wire should be used.

To find how many high hats you can use on a 120-volt circuit, you'll need to know the number of watts for each high hat. (Twelve high hats at 60 watts each would be using 6 amps; 720 total watts divided by 120 volts=6 amps.) Circuit capacity should not be pushed right to the limit, so most electricians try to leave a little cushion when calculating capacity. The rule of thumb is to allow 100 watts for each amp. That means a 15-amp breaker would be limited to 1,500 watts (a little less than the 1,800 maximum).

In addition to matching the correct wire gauge and breaker switches, remember to use the proper 120-volt receptacles. Grounded receptacles should be labeled by the manufacturer with the correct amperage and voltage.

When I add a wiring to an existing 15A breaker I use 12-gauge wire. It provides additional protection and costs almost the same as 14-gauge wire. When I add a standard circuit, I never use 15A ones but only use 20A ones.

[scarpi]

Here is my experience with this amp. I have a few month old B&K Ref 200.5 Series two amp. At first my amp was connected to the high current outlet on the back of my Panamax 5510 "AC Regenerator" and it routinely at turn on would peg the ampmeter past 15 amps and occassionaly would cause the Panamax to shut down the power to my system. This amp apparently draws alot of current at turn on. The specs state that the max current draw is 17.5 amps. So ok I thought it needs its own 20 amp circuit so I had a separate 20 amp line installed and only ran the amp on it while the rest of my system was still plugged into my Panamax on the 15 amp house circuit. I still found that occassionally the amp even blew the circuit breaker on its own dedicated 20 amp circuit at turn on. This line has heavier guage wire as required for a 20 amp line and the amp is the only item plugged into it. So I thought there had to be something wrong with the amp even though it was only a few months old so I called my dealer here in town. The place I bought it at is a high end home theater and audio store that also does custom home theater installs and the store is a huge McIntosh dealer. I mention this to just tell you that they are a knowledgable dealer. The store owner told me that they have experienced this issue with the B&K high current amps and that it is not really a problem with the amp. He told me that the proper way to install this amp is to use a 12 volt trigger cord between the preamp and amp. So he gave me a 12 volt trigger cord and I connected my B&K Ref 30 preamp to my B&K amp with it and the problem has been gone for a couple of months now. The preamp is left in the sleep mode when not in use and the amp power button is left in the on position and the preamp turns on the amp with no problem. When you put the preamp into the sleep mode it turns the amp off (standby). I hope this helps and sorry for being so long but since I found a solution to this problem I thought I'd share. Good luck! :T But I don't know what you would do if you don't have a preamp that has a 12 volt trigger output.

[scarpi]

Wait a minute, I just noticed that the original post was in 2006. I guess this problem has already been solved. :W

[Glen B]

It is really not necessary to quote all of that theory. Yes B&K recommends a 20A circuit, but in real world use, very few people are going to max out the amp. One's hearing is likely to reach the limits of its tolerance before that occurs. You're talking about a multichannel amp where all channels -- especially the surrounds -- are not called on to deliver maximum power at the same time.

With the last few action movies I watched, it was the center channel that carried most of the movie. The power meters of the main channels indicated little to no activity most of the time. The display on my line conditioner indicated a current draw of 2A for the entire HT system with volume at normal listening levels. I compared the accuracy of the line conditioner display versus my RMS reading DMM and it is quite accurate.

I concur on the use of 12 gauge wire exclusively versus 14 gauge.

[scarpi]

It is really not necessary to quote all of that theory. Yes B&K recommends a 20A circuit, but in real world use, very few people are going to max out the amp. One's hearing is likely to reach the limits of its tolerance before that occurs. You're talking about a multichannel amp where all channels -- especially the surrounds -- are not called on to deliver maximum power at the same time.

With the last few action movies I watched, it was the center channel that carried most of the movie. The power meters of the main channels indicated little to no activity most of the time. The display on my line conditioner indicated a current draw of 2A for the entire HT system with volume at normal listening levels. I compared the accuracy of the line conditioner display versus my RMS reading DMM and it is quite accurate.

I concur on the use of 12 gauge wire exclusively versus 14 gauge.

When I had my amp running through the Panamax, the ampmeter constantly read between two to three amps even while watching loud scenes from movies. So yes you would never get close to the 17.5 max amp draw while in use, but for some reason these amps draw an extreme amount of current at turn on (enough to peg a 15 amp ampmeter from my experience) and that is why I have found that not only does the dedicated 20 amp line help but also I found that using the 12 volt trigger solves the problem of blowing the breaker totally. I'm not an electrician but I guess by using the 12 volt trigger from the preamp, the amp is powered up from a standby mode and not a full cold turn on. But I bet the original poster has solved this issue since his post was a few years old. :T

[Glen B]

I have a 12,000 BTU air conditioner that operates on a 15A circuit and draws 24 amps at startup. I also have an air compressor operating on a 15A circuit that draws similar inrush current. I've never had issues with breakers tripping. These measurements were taken with my RMS reading Fluke clamp-on meter that reads inrush current. This shows that 15A circuits are pretty tolerant of inrush current.

[MTAtech]

2006? I didn't notice that either.