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Kev Williams
06-23-2014, 5:37 PM
I've had no problems with my Triumph and its equipment, 'till today, when everything to do with the laser shut down while I was cutting some wood. No power on the transformer. I checked my breaker, it wasn't tripped. I checked the on/off switch, and found it was frozen in the 'on' position. As I was puttering with it, I got a bright flash, a short "pffffttt" and the "click" of the breaker tripping. So I get on the phone with the place I bought it from, and within 2 minutes I'd decided they weren't going to honor their warrantee (I should be using a 7500w xformer with a 1900w PEAK power draw? I have a 3000w unit...)

Anyway, the unit's fuse also wasn't blown, and the breaker didn't trip until after the fact, so I figured the problem was the power switch. After opening the case, I found a hot lead disconnected from the switch, with the switch connector post still on it, dangling by itself, and the black spot on the case where it touched and tripped the breaker.

The factory had soldered the connectors to the switch. I guess they don't realize that when the post gets hot enough to melt solder, it's also hot enough to melt plastic. The post and everything else inside the switch moves, and so the switch contacts are compromised. And within a few months, the switch self-destructs...

Don't solder wires or terminals directly to plastic switches!

I installed a new switch and all's well...

Robert Walters
06-23-2014, 6:40 PM
Kev,

Switches are NOT suppose to get hot. Warm maybe, but not hot.
Sounds like the draw is higher than what it's rated for.


When you say "I should be using a 7500w xformer with a 1900w PEAK power draw?",
doesn't make sense (I'm assuming a typo there).


For example:
amazon DOT com/Rockstone-Power-Voltage-Transformer-Converter/dp/B00J0CF8W4/ref=pd_cp_e_2

This only lists ONE rating "5000 Watts", so assume that's peak, not continuous.

They also go on to say "max watts is at least 50% higher than your appliance",
so in this case you could gestimate that one it's about 3333W continuous, 5000 W peak.


You say you have a 3000W unit, but is that peak or continuous?
Using the same 50% continuous derating, means about 2000W continuous, less any losses.

If you happen to be drawing (let's say) 2100W on a regular basis, that's going to converted to heat eventually.
PEAK is intended for things like motor startup needs, and only last a few seconds, not minutes or hours at a time.


Let's say your step up transformer is a china special (quality is questionable).
For one, I'd derate right off the bat by half to be on the safe side.

Also, at 2000W cont on a 110VAC circuit would be 18 Amps.
Are you using a 15 or 20A circuit?

Is that switch you replaced rated for 18A or better?
Most I've seen are 10A and once in a while 15A.

Also higher rated switches are for resistive (lightbulb) loads, not inductive (motor).

I'd look at everything connected and do a little math to see how far you may be pushing it. A overheating transformer could potentially cause brown outs (voltage drops) in your laser, and premature wear on it's power supply.


BTW I used a variable controller rated at 1800 watts continuous on a 1500W load and it's outlet melted internally that I never saw it till I went to try to unplug the heating element and it wouldn't come out.

Bill George
06-23-2014, 8:31 PM
Solder should never be used for a electrical connection. The connection should be made mechanically secure before the solder is applied. This does not apply to electronics, but for connections that carry power or current as in this case. My guess as Robert has suggested the switch is not rated for the load.

Martin James
06-25-2014, 1:51 PM
his only lists ONE rating "5000 Watts"

20 amps x 120 volts = 2400 watts (on a good day)

I bought the one with the thickest cord

M

Bill George
06-25-2014, 2:59 PM
his only lists ONE rating "5000 Watts"

20 amps x 120 volts = 2400 watts (on a good day)

I bought the one with the thickest cord

M

Good switches are rated for Resistive load (iron or toaster), Inductive - transformers, florescent lights and such and Motor rated as to horsepower. There are also ratings for Incandescent lighting loads. It may be you need to think about installing a heavy duty relay to control your load instead of just a heavy switch.

Robert Walters
06-25-2014, 2:59 PM
I bought the one with the thickest cord

Heh, I've seen where they've used thick insulation so it looks like 14ga, but when cut open is only 18ga.

Kev Williams
06-25-2014, 6:05 PM
The switch I removed was rated 15 amp @ 250 volts. The switch I put in is rated 16 amps.

The original switch was compromised from the solder melting the switch body and loosening the contact spades. It was probably arcing badly inside every time I turned it on. So yeah, the switch was overloaded, but it wasn't exactly the switch's fault!

My watt usage: The laser's documentation states " <1.2kw " ... so lets say 1100. My blower uses 550. The chiller uses 100. The air pump 160 (I've used it twice ever). I get 1910 total...


When you say "I should be using a 7500w xformer with a 1900w PEAK power draw?",
doesn't make sense (I'm assuming a typo there). -- No typo. The CS rep from where I bought the xformer (a young lady if that makes any difference), told me that "because of the surge-draw of certain items, a 400% surge-factor must be added when choosing the wattage of the transformer, which means you should have ordered at least a 7500 watt unit". (1900x4=7600)

The only appreciable surge draw appliance is the blower, so figure 800 watts on spool-up? That's still less than 2200 watts (and the blower *almost* always gets turned on while the laser is idle). Everything always ran flawlessly. None of the plugs, outlets, or any other wiring within or outside the xformer show any signs of heat buildup, looks brand new. So does the fuse. But the switch looks like lightning hit it. It's the ONLY part showing any heat damage whatsoever.

Bill George
06-25-2014, 6:10 PM
That's when "Motor Rated" switches come in, they are rated for an Inductive load and typically motors draw anywhere from 3 to 4 times (or more) of FLA on start up. Once those switches have been cycled a few hundred times the contacts look pretty bad, and it goes down hill from there.