why do switches keep failing?

[aoristotle]

I have inherited an 80's vintage swimming pool. The pump is a 220v 1hp 0.75kW Hayward Superpump. I installed it new less than 5 years ago. It runs off a 30amp breaker. There are two lights, each: 110v, 500W, which also run off a (separate) 30amp breaker (there is also an outlet on the same circuit as the lights). What amperage switch is appropriate for these applications. I've tried 15 and 20 amp switches, and though it's no problem to change them out, I'm wondering why they keep failing.

 

[Giles]

I have inherited an 80's vintage swimming pool. The pump is a 220v 1hp 0.75kW Hayward Superpump. I installed it new less than 5 years ago. It runs off a 30amp breaker. There are two lights, each: 110v, 500W, which also run off a (separate) 30amp breaker (there is also an outlet on the same circuit as the lights). What amperage switch is appropriate for these applications. I've tried 15 and 20 amp switches, and though it's no problem to change them out, I'm wondering why they keep failing.

I had a, somewhat, similar problem with my barn breezway light system. It was fed by one switch. I replaced the switch five times in app. seven weeks.
After giving up and not using it for several months, a HVAC technician suggested that it could be caused by insects.
Sure enough, I discovered that ants were somehow entering the switch and basically insulating the switch contacts.
Strange that they were only entering the switch at nighttime
I switched off power and saturated the area with insecticide, installed a new switch, and had no more problems for a number of years
Not sure if this will help or not, but it sure surprised me

 

[JoeD]

1. The receptacles MUST be change to a 15 or 20 amp breaker. You are not permitted to have them on a 30 amp circuit even if you have # 10 cable.
What type switches are you using? Use the better quality ones instead of the 59 cent ones.

 

[aoristotle]

Giles- I have noticed ants swarming all over the switches.
JoeD- I was wrong. The breaker that has the pump attached is a 20 amp breaker. I was completely wrong about the lights. They run off a 20 amp GE arc fault(?) breaker, and the latest switch I installed actually works (but there are a lot of ants in it). The breaker was tripped, but you couldn't tell by looking at it.
Now... the 30 amp breaker that is in the panel runs to a well pump, then to two receptacles and a switch that works two light fixtures (outdoor floods-but now only regular incandescant light bulbs are in them- so maximum 200W per fixture). It may also run to another outbuilding. but I'm not sure. I wouldn't be surprised if the rig is not "up to code." I live in a rural area where there are no inspections. However, apart from replacing switches and other standard maintenance, the system has functioned without incident for 30 years+.

 

[Giles]

Giles- I have noticed ants swarming all over the switches.
JoeD- I was wrong. The breaker that has the pump attached is a 20 amp breaker. I was completely wrong about the lights. They run off a 20 amp GE arc fault(?) breaker, and the latest switch I installed actually works (but there are a lot of ants in it). The breaker was tripped, but you couldn't tell by looking at it.
Now... the 30 amp breaker that is in the panel runs to a well pump, then to two receptacles and a switch that works two light fixtures (outdoor floods-but now only regular incandescant light bulbs are in them- so maximum 200W per fixture). It may also run to another outbuilding. but I'm not sure. I wouldn't be surprised if the rig is not "up to code." I live in a rural area where there are no inspections. However, apart from replacing switches and other standard maintenance, the system has functioned without incident for 30 years+.

Not saying ants are your problem---but worth checking. Ants secrete a "perfect insulating solution" to mark their trail. So when they go across the contacts they are insulated.
Out of cuerousity, I disected a "bad" switch and found it looked new I then lightly sanded the contacts and it then tested good but I threw it away.
The technician informed me that MANY AC relays were replaced for this reason.