Space heater rocker switch - Page 1
Forum section: electronics / repair

author: jmurphy
author_rank: Contributor
timestamp: January 15, 2021, 07:19:10 pm
content: I have a small space heater (120 VAC. 1500 W, 60 Hz). It works great but I’ve had to replace the on/off rocker switch twice. It’s a DPST rocker switch. The switch illuminates when turned on. The panel cutout is approximately 22 mm x 30 mm. The rockers often spark when switched which is why I assume they don’t last long. Is there a specific replacement switch that would have better longevity?

author: Gregg
author_rank: Super Contributor
timestamp: January 15, 2021, 07:46:36 pm
content: I have the same switch in my espresso maker and it used to melt down way too often. My solution was to install a NOS double pole relay to do the heavy switching. Using a two pole relay will allow the two sets of contacts to share the load. In my case there are two 120 volt elements in parallel and I wired each element to a relay contact. I tried many rocker switches and the best ones only lasted about a year; cheap ones about a month. The relay has been reliable for over 3 years of daily use.

author: Alti
author_rank: Frequent Contributor
timestamp: January 15, 2021, 09:46:51 pm
content: That is 12.5A current. Are you sure it is rated at those currents? The resistive heater should not damage contacts when ON->OFF (low inductance). If it is IR (quartz) then it could have inrush but that is at OFF->ON and there is no sparking.Why does it switch both poles?Is it because of some regulations in US? I live in EU and heater switches, lamp switches and everything that is enclosed is single pole here. My washing machine is double pole

author: Gregg
author_rank: Super Contributor
timestamp: January 16, 2021, 12:25:50 am
content: Quote from: Alti on January 15, 2021, 09:46:51 pmIn many illuminated rocker switches, there are two terminals for the pilot lamp but sometimes there are three terminals; the third for the return power to the lamp.

author: andy3055
author_rank: Super Contributor
timestamp: January 16, 2021, 01:54:39 am
content: I have seen that installing a capacitor across the contacts will reduce the arc. Try something like a 0.005 uf/400 v cap.Edit: make it .047 or .05 uf, 400v.

author: jmurphy
author_rank: Contributor
timestamp: January 16, 2021, 04:50:53 am
content: Gregg is right that only 1 pole is used for the switching. The second pole is necessary for the neutral to the switch light.It is a resistive wire heater (not quartz) with a fan. It is an older model with no micro-controllers. Looks like there is also a tilt switch too.

author: Alti
author_rank: Frequent Contributor
timestamp: January 16, 2021, 04:07:23 pm
content: Quote from: jmurphy on January 16, 2021, 04:50:53 amDo you need a switch light?If not, parallel both poles. Just make both paths share similar currents. Of course you need two pieces of cable with proper connectors for the job. Get those from some old washing machine wiring loom.Before that make sure the rocker switch is a complete double pole rocker switch and not some stripped version single pole with light.Then each pole draws under 7A which should last more or less forever.

author: jmurphy
author_rank: Contributor
timestamp: January 16, 2021, 04:50:53 pm
content: I'd like to keep the light on the switch. Otherwise I forget to unplug it.fyi : The load is not all resistive because there is a .36A fan motor too.