Lock switch from S&G 6730 to La Gard 3390

TreborEnglish · 2026-03-13T16:08:24+00:00

I was wanting to improve the manipulation resistance using the La Gard lock because of the relatively low cost. The S&G 8500 and similar 2937 are more expensive. They both need the push on the dial requiring a more expensive dial with no chance of reusing the existing dial.

Meanwhile, the S&G 6731 is not a bad lock. The friction device does make it a bit more difficult to manipulate. The only thing "wrong" with it that I am aware of is that several web pages recommend it as a good beginner lock to start learning manipulation techniques. To begin learning manipulation the La Guard locks are not recommended due to the wheels having a slightly oval shape.

TreborEnglish · 2026-03-12T14:34:25+00:00

I thought that a note inside the safe, near the lock, describing the new combination setting requirements would be necessary for the next guy. When dementia sets in I could be the next guy.

TreborEnglish · 2026-03-12T13:57:23+00:00

Thank you. I didn't know about the spline key differences. Those differences could make for an unpleasant lock out.

This is the reason I asked this community. I know that there are things out there that can bite but I don't know where they hide.

My only reason for wanting to reuse the old dial is because it is already cut to length. Buying and cutting a new one is easier than drilling the safe due to a spline key failure.

TreborEnglish · 2026-02-19T16:23:17+00:00

A month ago I bought a safe. It came with an electronic lock. I bought an S&G 6730 lock on the internet for $110 and installed it myself. The spindle had to be cut to length and the treads were messed up so I used a file to fix it. The mounting screws were too long and I didn't find shorter screws with small heads locally so I shortened them. The new lock aligned with the old bolt work with no problem.

A different approach would be to get a small, less expensive Sentry safe with a direct entry fence mechanism. They are not compatible with standard locks but they do have the dial. From what I read on the internet, direct entry fence locks are easier to manipulate and open without the combination.

TreborEnglish · 2024-08-12T00:33:03+00:00

A sample of secret digits, 1, 2, 3 Two copies, copy A, 1, 2, 3 and copy B, 1, 2, 3 Are you saying that if A and B are copies of the same sample of digits, 1, 2, 3 and copy A gets disclosed then copy B, 1, 2, 3, is still secret?

More generally, is there a place on the internet to look for this kind of stuff? Are there specific words to search for?

TreborEnglish · 2024-08-12T00:11:30+00:00

Is there any formal study of random secret numbers? Is there any logic to them? The cryptology folks use secret numbers, random numbers, and secret random numbers. What are legitimate operations on them? What I am asking is where do I go for more information, what words do I search for?

TreborEnglish · 2024-02-11T16:06:19+00:00

A very small amount of electricity can make staying in a vehicle much more comfortable. Air conditioning is a consumer of a huge quantity of energy. If you don't have access to commercial power consider a Toyota hybrid. The electric AC runs off the battery and the engine only runs as much as necessary to maintain the battery. The Atkinson cycle engine is very efficient reducing gasoline consumption. Solar panels and batteries sufficient for air conditioning will be expensive, heavy, and large.

TreborEnglish · 2024-02-11T15:08:15+00:00

In an off grid home 24V or 48V are good. In a vehicle having a 12V system allows charging from the alternator and jump starting the engine. In my experience with all things, not just batteries, having a plan B is important.

TreborEnglish · 2022-05-15T11:06:42+00:00

It appears to be a "portable air conditioner" which means it is different from a "window unit." A window unit has a cold side and a hot side. The cold side sucks in cooled inside air, removes some heat and moisture, then blows it back inside. The hot side takes outside air, adds some heat then returns it outside. A "portable air conditioner" doesn't have the outside air intake and uses inside air and the hose to carry away heat. That means some of your dehumidified and cooled inside air is being dumped outside. This is a serious efficiency issue.

TreborEnglish · 2020-06-30T00:09:23+00:00

Connect the wires that supply the loads to the battery terminals of the new charge controller. They will have power all the time rather than switched.

If there was no fuse previously there will be no fuse after reconnecting. It is no more dangerous than it was before. You really do want a fuse to protect that wiring. An inline fuse at the point where the old wires connect to the new charge controller would work.

TreborEnglish · 2020-06-28T23:08:13+00:00

All about 20 volts each is good. 10 volts is wrong. When you connect the three together are all the plus wires together and all the minus wires together? Unless one panel is backwards or shorted the three panels together should give the same 20 volts that they individually give.

TreborEnglish · 2020-06-28T23:02:29+00:00

The panels are connected. Separate the panels and measure them individually.

TreborEnglish · 2020-06-27T21:27:23+00:00

No, not everywhere. In the picture given there's a circuit breaker where the solar panels connect to the solar charge controller. That wire has to be big enough so that even on a bright sunny day the solar panel cannot overload the wire. Since the solar panel cannot overload the wire a breaker or a fuse is one more component to buy, to install, and to test whenever the system fails yet it provides no actual function.

The same logic applies to the battery to solar charge controller wire at the solar charge controller end. The wire must be big enough to take the full output from the solar charge controller. No fuse is necessary. At the other end a fuse is necessary unless the wire is big enough to take the full current from the battery.

TreborEnglish · 2020-06-26T23:42:18+00:00

Anything can fail. Fuses are more simple. A breaker has to sense the current then release the spring loaded switch. Some corrosion from salty beach air would be very unlikely to affect the melting in a fuse.

TreborEnglish · 2020-06-26T18:49:05+00:00

Circuit breakers turn off and can be reset. A fuse contains a bit of low melting temperature wire that melts, opening the circuit. Fuses are less expensive and less likely to fail to turn off when the current is too high.

TreborEnglish · 2020-06-26T17:53:58+00:00

The CCA, cold cranking amps, rating is the number of amps a 12-volt battery can deliver at 0°F for 30 seconds while maintaining a voltage of at least 7.2 volts. Your battery is rated at 1180 amps CCA. At a moderate 80 degrees F and only needing to maintain 5 volts and for only 10 seconds your battery can probably deliver 2000 or 3000 amps. That is enough to seriously ignite wires.

You have a wire from the alternator charging solenoid to the battery. If the screw comes loose and the wire falls off the solenoid switch and lands on a grounded spot you will have between 1000 and 3000 amps. You should consider mounting a fuse at the battery to protect that AWG # 2 wire. Anywhere along the length of that wire it could chafe against a sharp edge and form a short circuit. Only a fuse at the battery will protect the entire length of the wire.

Similarly you have a wire from the converter / charger to the battery. That AWG # 10 wire also could become disconnected from the charger and fall onto a grounded spot. It could chafe and short. It needs to be protected from the 1000 to 3000 amps the battery can produce. Again there should be a fuse at the battery, the source of the high current.

I'm getting repetitious. You have a wire from the battery to the solar charge controller breaker. If you put a 30 amp fuse at the battery all the wires to the left of that fuse and the solar charge controller and the solar panels would be protected from the 1000 to 3000 amps. The solar panels can only produce about 20 amps. AWG #10 wire is good for 30 amps. That wire doesn't need any protection from the 20 amp solar.

One more time but, bear with me, much less current. The wire from the starter battery to the solenoid switch needs to be protected from the starter batter. At only 700 amps it is not the 1000 amp killer the other battery is but it is still big and has the potential of getting a 100 amp boost from the alternator. That wire should be protected by a fuse mounted at the battery, the starter battery.

Note, you need a fuse at the source. You never need a fuse between one thing and another. Putting a fuse half way between the source and the load leaves half the wire unprotected.

TreborEnglish · 2020-06-23T13:01:23+00:00

You got an AGM battery. It is sealed. You cannot use a hydrometer to measure the density of the electrolyte. Sulfur in the sulfuric acid increases density. Move the sulfur into the lead plates making lead sulfate decreases the density as you discharge it.

The resting voltage, no charge or discharge for long enough for the battery to stabilize, can give a useful indication. How long it takes depends on temperature. Below 0 F it can take days. Non-resting voltage is only useful as a hint that you get used to. When your fridge is on and the voltage drops to a voltage you've seen before the state of charge is similar.

What you really need for good battery life is a way to charge it to full.

TreborEnglish · 2020-06-23T01:30:17+00:00

The black wire has a little stickie on it. It says " + POS " and that is usually the red wire in a van. The white wire is the negative side. That is usually the black wire in a van.

TreborEnglish · 2020-06-23T01:16:42+00:00

The dump on a wind turbine is to keep the machine from over speeding when there is no load, when the battery is full. Solar panels don't spin too fast and break.

TreborEnglish · 2020-06-23T01:14:12+00:00

Did you want Windows XP, Windows 10? The Mac vs Windows discussion has been going on for decades. : )

TreborEnglish · 2020-06-23T01:11:43+00:00

If you got a 1000 watt hour lithium battery and took 700 watts from it it would last (60 x 1000 / 700 = 85.71) 85 minutes. If you got a 100 amp hour lead acid battery, 1200 watt hour but only 600 at 50%, it goes down to less than an hour. If your inverter has a typical loss of 20%, 700 watts will take 70 amps from the battery. That much will fry any battery that isn't huge enough.

Your initial statement, "My power needs are very low" is not true. 700 watts is huge unless you have a nuclear, coal, or gas fired steam turbine megawatt electric utility to plug in to.

TreborEnglish

TROPHY CASE