Propane solenoid question

[svMarite]

Hey cruisers
I recently put my hand in the tank locker to turn on my bbq line valve, burned my finger on the solenoid valve. Is that normal for that to be so hot to the touch? As liveaboards, we leave our system hot and turn on the gas from remote next to galley.

I'm writing because clearly I think its abnormal. Been on boats for over 20yrs with plenty of water under my keel.

Thoughts, suggestions ...no judgements or ideas on other stuff please. Pls just Answer the question if you have real experience knowledge.

[steve77]

Originally Posted by svMarite

Hey cruisers
I recently put my hand in the tank locker to turn on my bbq line valve, burned my finger on the solenoid valve. Is that normal for that to be so hot to the touch? As liveaboards, we leave our system hot and turn on the gas from remote next to galley.

I'm writing because clearly I think its abnormal. Been on boats for over 20yrs with plenty of water under my keel.

Thoughts, suggestions ...no judgements or ideas on other stuff please. Pls just Answer the question if you have real experience knowledge.

Not sure what system you have installed. On our Trident propane control system, the remote located in the galley energizes the solenoid. The solenoid is only energized when turned on at the panel. You say "we leave our system hot and turn on the gas from remote next to galley", but that really should not make a difference. If the circuit breaker is turned on, the solenoid should not be energized until turned on with the remote.

Our solenoid uses about 1 Amp of current. It can get warm if used for a long time, but it only starts to get warm when turned on at the panel.

Do you have a method of measuring the current to the solenoid when it is not turned on at the panel? Some type of clamp-on ammeter that will read DC? With the circuit breaker on and the system turned off at the remote panel, the solenoid current should be zero. Also, do you have one of those temperature reading guns that you can buy at Harbor Freight? If so, measure the temperature of whatever you burned your finger on and see what it actually is. Again, unless the solenoid is turned on at the remote panel, the solenoid should be ambient temperature.

It could be normal, or it may not be. Let us know what system you have installed. If you can check the solenoid current when turned on and when turned off, and the temperature the solenoid reaches, that would be helpful.

Cheers!

Steve

[svMarite]

Good idea Steve thanks. Yes Trident system. I have athe tools, let me check that out and post in a bit with my discovery.

[a64pilot]

They get hot, that’s normal. They get hotter if left on with no gas flow as the gas is cold right at the tank because of phase change and pressure drop, so don’t leave one on without gas flow.

[BlackHeron]

Our solonoid draws 5+ watts to keep open. A solonoid is simply a coil of wire that is an electromagnet that pulls a plunger against a strong spring to open and close a valve. It takes power to hold the plunger open against the spring and that power is transferred into heat in the long run.

Gas solonoids are designed to fail safe, which is to close the valve again when power is removed since the spring will automatically close the valve and shut the gas off when deenergized. Some solonoid valves work the other way but that wouldn't suit the purpose of a safety system that is designed shut the gas off.

5 watts is a lot of power actually, and over time a lot of heat will build up. The flow of the gas will tend to cool the solonoid valve but when you are not cooking or running a heater there is no gas flow and the valve will heat up until it reaches some steady state where the ambient air is cooling it but that depends on air flow and the temperature of the air. In an enclosed space like a propane locker there may not be a lot of air flow and the temperature inside the locker will tend to get fairly warm too. Our solonoid is outside under a waterproof cover on the stern rail, and still it is quite warm to the touch when cooking and if it is forgotten and left on for hours is almost too hot to touch.

The system is designed to be turned on when you want to cook, and then turned off again immediately when you are done. With the solenoid on you have no protection against leaks unless you also have a smart solonoid panel interfaced with a gas sniffer(s) in the bilge and maybe below the appliance. Furthermore 5 watts is about half of an amp. That's a lot of power and in the course of a day it in excess of 10 amphours being wasted for nothing.

[svMarite]

Outstanding response! Thank you.
As mentioned before I dont know how we became complacent to not shutting it off every time, as we had for years before. Maybe getting a little burn served me right to get back, a sign from the sailing gods...
Thanks guys for these educational pass-ons. The real bennie of this forum.

[NYSail]

Turn solenoid breaker on when cooking. Turn solenoid breaker off when finished. Dont mess with gas.

[BlackHeron]

Originally Posted by NYSail

Turn solenoid breaker on when cooking. Turn solenoid breaker off when finished. Dont mess with gas.

Our solonoid panel also is a smart gas-sniffing device with a remote sensor in the bilge and an optional second zone for another location. It doesn't just sense propane, but other dangerous gasses and vapors and will emit an audible alarm and immediately shut off the solonoid if it is on. The solonoid is controlled by an on/off switch on the panel.

We leave the panel on whenever we are on the boat. As well as a separate CO detector panel, but aleays shut off the solonoid using the button on the panel when we are done cooking.

I just checked the power consumption of our solonoid and it is closer to 7 watts, not 5 as I said above. That's a lot of juice. But the sniffer panel itself draws an additional 5 watts even when the solenoid is off (or even physically disconnected from the circuit) because that gas sensor in the bilge is a power hog I guess, and whatever electronics are active inside panel itself. I bet if we added a second sensor to zone 2 on the panel it would draw even more power.

I am not happy with this electrically inefficient gas sensor & panel but I guess that is the price to pay for safety. I suppose I could put a switch in line with the power feed to turn off the entire panel when we are not using the LP but then we would lose the protection of the explosive fume detector. It will detect many other explosive gasses such as gasoline, alcohol, acetone, various paint thinners, butane and other stuff that might be stored aboard and could possibly spill in a locker and make its way to the bilge if they were heavier than airnornthe biat was really closed-up tight. It will even alarm if it senses a lot of hydrogen gas such as if the batteries are being excessively overcharged. But hydrogen is lighter than air so there would need to be a lot of it built up in a closed-up boat for it to trip a sensor down in the bilge.

The instructions that come with the device say to keep it powered up whenever the boat is occupied:

"CAUTION: NO POWER ON/OFF SWITCH IS PROVIDED FOR THIS UNIT. TO
FUNCTION AS INTENDED, THE S-2A MUST BE CONNECTED TO A CORRECT
POWER SOURCE, AND FOR MAXIMUM EFFECTIVENESS, BE POWERED AT
ALL TIMES WHILE ABOARD. IF POWER IS ON AND LEFT UNATTENDED FOR AN
EXTENDED PERIOD OF TIME, BATTERY POWER MAY BE DIMINISHED."

https://www.fireboy-xintex.com/s2a/

[svMarite]

Yes we have the same CO2 sensors throughout the boat. I like the system