How many watts can a 300w rated Legrand dimmer really handle?

[scania164]

I've got some Legrand dimmer modues, 7354-46.
They are rated at 300w but with the setup that I have I'd really like to use one of them on a circuit with a load of 420w.
I've read before that MK dimmers can handle 200% of their rated load.
Anyone know how much these Legrand dimmers can handle before you're really to risk causing damage?

 

[telectrix]

i would not even attempt to overrun any dimmer. in my experience, most struggle to cope with their rated load, let alone an overload.

 

[Paultrim123321]

I would say if states 300W then that should be the largest load you put through the switch, whether there is a tolerance or not.

If the manufacturer was confident in their device at 200% then they would rate it at that wattage surely?

 

[kingeri]

Unless you specifically want to make money from repeated call-outs, then don't do it. I always take the rating of them with a pinch of salt and go lower with the load.

 

[telectrix]

seems i'm not the only one that's wet the bed this a.m.

 

[kingeri]

I can't lie in any more, I always wake up at 7am or earlier, but to be honest this is the only time I get to myself these days. Until the wife and my boy emerge I can do whatever I want, it's so cool man. Apparently it's inappropriate to start drinking at this time though. Shame.

 

[SPARTYKUS]

Morning Tel :waving:

 

[SPARTYKUS]

Fitted a dimmer (400W) 3.5 year ago - got asked to replace as busted - it was controlling (happily) a 200w halogen light. This had popped and the nugget had put a 500w one in.

I agree with above posts re: handling rated loads they seem fragile at best.

 

[Octopus]

I've got some Legrand dimmer modues, 7354-46.
They are rated at 300w but with the setup that I have I'd really like to use one of them on a circuit with a load of 420w.
I've read before that MK dimmers can handle 200% of their rated load.
Anyone know how much these Legrand dimmers can handle before you're really to risk causing damage?

75% of the rated value

 

[telectrix]

that's the figure i wrk to, unless the load is halogen spots, then i drop to 60% of rated load.

 

[UNG]

Dimmer modules like those mentioned when co-located in grids usually need de-rating sometimes to 30% of the rated wattage depending on how many dimmer modules are fitted in the grid.

From past experience dimmers rarely last when run close to their maximum ratings and I can only think the 200% mentioned would possibly be a short term rating to cope with inrush when turned on and / or the brief peaks caused by lamp failure.

 

[Knobhead]

Madness to overrate them. Like Murdoch I’d go for 75% of rating.

The dammed things are unreliable at the best of times.

 

[Silly Sausage]

Dark glasses are 100% reliable.

 

[scammell man]

Down rating depends on load type. Always down rate by power factor of load, so 75% is a good starting point ( if dimmer can handle this type of load at all). Obviously not applicable for resistive load
I think Philips dimmable LEDs state to down rate by around 90 %ie 30w load on a 300w dimmer.

 

[7029 dave]

300w...lol

 

[Darkwood]

What ever happened to the reg's and following manufacturers guidelines you are only asking for trouble - heat dissipation is a major issue with dimmers and do often incur derating factors when grouped ... the hypothetical 200% you may have heard may be a short term loading tolerance before damage occurs and not continuous operational loading. Its similar to the KVA rating on say a 110v transformer these are actually in some cases misleading as its not a continuous load rating but a short term value... it is common to find a much lower KVA continuous rating in the instructions or on the plate but ironically tey advertise for the higher value of which they can't maintain.

 

[scania164]

The load that I wanted to put through the dimmer was 420w, which I thought might have been ok as manufacturer's ratings tend to err on the side of caution, wishful thinking perhaps.
The common consensus doesn't recommend this so I decided to play it safe and went with a 240w max load.

 

[telectrix]

why not use a 700w dimmer.