Determining the switch rating for a lamp

In summary: Glad things worked out eventually. Just FYI, at this point I would have used an ohmmeter to test whether the switch is working properly.
  • #1
mar2194
10
0
I'm in the process of repairing a lamp that I found with a broken switch. I know the lamp mechanism is functioning because I've bypassed the switch and plugged it in and it works fine. I needed to buy a new switch and they all have a current rating. I'm using 1 60 W bulb with a standard North American 125 V outlet. I thought P = IV --> I ≈ .5 A. Using this info I purchased a toggle switch rated at 5 A for 125 VAC (so at least 5 amps of current can flow through it right??) and tried adding it to the lamp. Didn't work! Does anyone know what I might be doing wrong or how to determine the current rating for the switch I'm attempting to add?

Any help is appreciated. I bought the switch at RadioShack if anyone is interested. Thanks!
 
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  • #2
NVM problem solved; there were 3 connectors for 2 different voltage ratings. I just fiddled with it a little.
 
  • #3
mar2194 said:
I'm in the process of repairing a lamp that I found with a broken switch. I know the lamp mechanism is functioning because I've bypassed the switch and plugged it in and it works fine. I needed to buy a new switch and they all have a current rating. I'm using 1 60 W bulb with a standard North American 125 V outlet. I thought P = IV --> I ≈ .5 A. Using this info I purchased a toggle switch rated at 5 A for 125 VAC (so at least 5 amps of current can flow through it right??) and tried adding it to the lamp. Didn't work! Does anyone know what I might be doing wrong or how to determine the current rating for the switch I'm attempting to add?

Any help is appreciated. I bought the switch at RadioShack if anyone is interested. Thanks!

What do you mean it doesn't work? It sound like it's rated fine. If it weren't rated high enough, it would catch fire, not "doesn't work".

BTW, you do know that the hot lead for lamps needs to go to the inner button on the bulb socket, right? Not to the outside screw part. That's why lamps in the US use a polarized 2-prong power cord.
 
  • #4
Ah, glad it works now. Does my comment about the hot/neutral polarity make sense?
 
  • #5
berkeman said:
Ah, glad it works now. Does my comment about the hot/neutral polarity make sense?

Yah, all I was doing was taking a spliced wire and putting in a switch. When I said it didn't work I just meant that when I flip the switch, nothing happens. I realized I was using the portion of the switch that was rated for 3 amps @ 250 V instead of 6 amps @ 125 V. However, the switch didn't fit the hole so I'm going to buy another one that will be rated at .5 amps. Will that be rated high enough?
 
  • #6
mar2194 said:
Yah, all I was doing was taking a spliced wire and putting in a switch. When I said it didn't work I just meant that when I flip the switch, nothing happens. I realized I was using the portion of the switch that was rated for 3 amps @ 250 V instead of 6 amps @ 125 V. However, the switch didn't fit the hole so I'm going to buy another one that will be rated at .5 amps. Will that be rated high enough?

That sounds kind of marginal. I'd go with a rating at least 2x or higher than the steady-state current. And be sure to mark the lamp for 60W bulbs maximum or similar.
 
  • #7
mar2194 said:
... I purchased a toggle switch rated at 5 A for 125 VAC (so at least 5 amps of current can flow through it right??) and tried adding it to the lamp. Didn't work! Does anyone know what I might be doing wrong or how to determine the current rating for the switch I'm attempting to add?
Glad things worked out eventually. Just FYI, at this point I would have used an ohmmeter to test whether the switch is working properly.

mar2194 said:
Yah, all I was doing was taking a spliced wire and putting in a switch. When I said it didn't work I just meant that when I flip the switch, nothing happens. I realized I was using the portion of the switch that was rated for 3 amps @ 250 V instead of 6 amps @ 125 V. However, the switch didn't fit the hole so I'm going to buy another one that will be rated at .5 amps. Will that be rated high enough?
I'll echo what Berkeman said about the 2x rating. Also, any chance you'll use the lamp for a 100 W or 150 W bulb? I would figure out the current at 150 W, and go to twice the current rating of that. So, 1.25A @ 150W, try to get a switch rated for 2.5 Amps. Or if you're absolutely sure 60 W is the maximum you'll use, then 1 Amp.
 

What is a switch rating for a lamp?

A switch rating for a lamp refers to the maximum amount of electrical current that a switch can safely handle without overheating or causing a fire hazard.

Why is it important to determine the switch rating for a lamp?

Determining the switch rating for a lamp is crucial for safety reasons. If the switch is not rated for the amount of current that the lamp requires, it can cause the switch to overheat and potentially start a fire.

How can I determine the switch rating for a lamp?

The switch rating for a lamp can be determined by checking the wattage and voltage of the lamp. The switch rating should be equal to or higher than the wattage and voltage of the lamp.

What happens if the switch rating is lower than the lamp's wattage and voltage?

If the switch rating is lower than the lamp's wattage and voltage, there is a risk of the switch overheating and causing a fire. It is important to always use a switch with a rating that matches or exceeds the lamp's requirements.

Are there any other factors to consider when determining the switch rating for a lamp?

In addition to wattage and voltage, it is also important to consider the type of switch and the environment in which the lamp will be used. For example, a switch used in a damp or wet location may have a different rating than one used in a dry location.

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