In my very modest build of an electric HLT I've taken some notes. Putting them down here with some pics for reference because HBT will last longer than my computer.
Quite sure this is not the fastest way to heat HLT water and maybe I'll look back and laugh at myself later. I love that there is no blast furnace propane burner going and that this is very quiet. Posting the results of my second heating.
8 gallon aluminum tamale pot, not insulated (local grocery store)
Sight gauge/thermometer (BrewHardware)
1/2" ball valve (BrewHardware)
1500 watt hot water heater element (Lowes)
Power source. 110vac/15A garage GFCI outlet. Element should be drawing around 12 amps. All wiring 14 gauge, connectors, switch and outlet rated at 120vac/15amps. Wiring never got warm. The connector on the HLT heating element got slightly warm.. Not hot at all. I used liquid tape to pot it. It is holding up fine. Don't think I need to worry about the stuff. It does take days to cure.
Ambient air temp was 72F
Water: 7 gallons, start temp 70F
Readings taken from an anolog thermometer installed 1" above the bottom of kettle
1305-1315 - 80F
1315-1325 - 96F
1325-1337 - 110F
1337-1345 - 119F
1345-1355 - 133F
1355-1401 - 140F
1401-1406 - 145F
1406-1415 - 156F
1415-1425 - 168F
1425-1436 - 181F
1436-1447 - 195F
Time for a decent mash water starting temp 168 is 1hr 20 minutes. Could go with a lower temp but would rather be higher than lower starting out. Easy to go down, hard to go up. Patience works. It's also based on 7 gallons.. Biggest 11 gallon batch I've made to date only used around 6-6.5 mash water and around 7 gallons sparge. Should easily raise sparge water to required temp during the mash period. Five gallon batches will take less time. I'll have to test that as well.
Final reading 195F on both the installed thermometer (botom of pot) and a digital thermometer submersed 1" below the water.
It cost about 20 dollars to go electric on this thing. If I had more power to play with, would go up a few watts on the heating element. I do have some 20 amp plugs in the kitchen and could go up to a 2000 watt element with that but don't want to be brewing in the kitchen or running an extension cord from there. This will have to do for now.