High amperage draw alarm

[Simi 60]

Second time in two years I forgot to turn off the 240v domestic hws when done.
Result being the low voltage alarm on the victron 702 battery monitor just went off and we were pulling 90 amps and probably had been for an hour.
Not good.

Haven't found info yet but can the 702 or some other device be set up to alert if there is a larger than normal amp draw from the house bank?

Or probably better still, flick the breaker off when the hws is done, manual on when conditions are right.

[Terra Nova]

Take the water heater off the inverter circuit.

[a64pilot]

Originally Posted by Simi 60

Or probably better still, flick the breaker off when the hws is done, manual on when conditions are right.

Many of us with 30 amp boats have to power manage, we can’t run our toaster, both AC’s and the water heater, vacuum cleaner etc.
We quickly got into the habit of looking to see how many amps are being drawn before turning on any high amp device, isolating is way more complex electrical than needed I think, and even then is only partially effective, cause for us the toaster and vacuum can both draw excessive amps as can the heat gun when I’m shrinking a splice etc. You can’t isolate every potential high amp draw.

I get up in the morning and when we are on shorepower, turn on the water heater, and then an hour later, turn it off before the AC comes on.
I have contemplated putting it on a simple timer, but haven’t cause I don’t think I need to. Not having hot water once in a blue moon in hot weather isn’t a big deal for us.

[Simi 60]

Originally Posted by a64pilot

Many of us with 30 amp boats have to power manage, we can’t run our toaster, both AC’s and the water heater, vacuum cleaner etc.
We quickly got into the habit of looking to see how many amps are being drawn before turning on any high amp device, isolating is way more complex electrical than needed I think, and even then is only partially effective, cause for us the toaster and vacuum can both draw excessive amps as can the heat gun when I’m shrinking a splice etc. You can’t isolate every potential high amp draw.

I get up in the morning and when we are on shorepower, turn on the water heater, and then an hour later, turn it off before the AC comes on.
I have contemplated putting it on a simple timer, but haven’t cause I don’t think I need to. Not having hot water once in a blue moon in hot weather isn’t a big deal for us.

This is exactly what I do now, apart from two times, and without the shore power.

My comment was meant to ask is there some sort of mechanism that will flick the hws breaker off when done so as to avoid issues with me forgetting again.

Leaving the switch panel door open is enough of a reminder usually, yesterday apparently not.

[Simi 60]

Originally Posted by Terra Nova

Take the water heater off the inverter circuit.

In summer, solar panels will punch in around 80amps , not quite enough to do the hws entirely so needs some inverted power.
If timing the hws right I will usually have the hws done and batteries at 100% by lunchtime.

Its only rainy days and winter that the genset is required.

[a64pilot]

I have been looking at some panels to replace my existing amp meter, some are pretty sophisticated reporting Hz rate, KWH used etc. I won’t to think I’ll find one with an alarm at a set amps, so when we forget to turn off an AC unit before we vacuum or something we will know prior to the CB tripping.
Wouldn’t be so bad if a 30 amp cable could hold 30 amps, but they can’t, the connection is the weak link and burns. Smart plug only works on the Boat end of course.

I ordered this one, it has an alarm function, but only will flash it’s back light I think. I’d like one that will set off a buzzer.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[smac999]

If you found a system that set off a high current. Alarm. It would go off every time you turned the Hwt (ank). on. (What is a hws?). There wouldn't be a way to know when you are done using hot water. Unless you put an electrical sensor on your shower tap.

The best would be a high current sensor. with a timer set at 30mins or something like that... putting an ac relay on the hwt line shoul'd. Be that hard.

But you have to find such a system. Czone would probably do it, for a couple grand.

[Simi 60]

Originally Posted by smac999

If you found a system that set off a high current. Alarm. It would go off every time you turned the Hwt (ank). on..

It would do if it was being pulled from the batteries which is the point.

If i understand how our mppt charger, inverters work, if most of the power was being provided from solar then bugger all comes from the actual batteries.
It would be the same when the genset is on.

. (What is a hws?).

HWSystem

[a64pilot]

I’d want an alarm that if I exceed 25 amps total draw will alarm, alarm should of course be user adjustable. I can figure out why and take corrective action. That would not be hard to build and I bet exists, just finding it is the issue.

[a64pilot]

How does the joke go? Found after a brief search
https://www.amazon.com/Blue-Sea-Syst...+current+alarm

[Simi 60]

Originally Posted by a64pilot

How does the joke go? Found after a brief search
https://www.amazon.com/Blue-Sea-Syst...+current+alarm

Thanks
Now to find the $10 version like in this thread

http://www.cruisersforum.com/forums/...rm-202270.html

[a64pilot]

I ordered the 1838 OLED from Hodges Marine, I’ll let you know how well it works, but I haven’t ever gotten anything from Blue Seas that wasn’t a quality product.
It has high current and high and low Hz alarm set points I believe.
https://www.hodgesmarine.com/Blue-Se...-p/blu1838.htm

[Mike Banks]

There are two types of electric systems, one has no storage capacity and heats the water passing through the system. This is thetyoe most likely to be found on some smaller vessels that spend a lot of time in a marina where domestic power is available.

The other type is a storage type. Both can be fitted with cut-off switches, of different types.

The heat-as-you-use type can be fitted with a flow switch that only allows the heater to be turned on when someone opens a hot tap. As soon as water flows, the heater turns on. I think it is a pressure operated switch but I am not certain--I just know they exist.

The third option seems a bit obvious--rig the system through a timer switch. They can be bought just about anywhere.

[a64pilot]

I have never seen an electric on demand water heater, the draw would be enormous I think.

[StuM]

Originally Posted by a64pilot

I have never seen an electric on demand water heater, the draw would be enormous I think.

Yep, multi kW even for the smallest ones

https://www.bosch-climate.us/product...nt-of-use.html