/ Cold weather start, with glow plugs and block heater. Why does my tractor not start at minus 20 C?
#81
lpakiz
Gold Member
- Joined
- Jul 25, 2017
- Messages
- 384
- Location
- Greenwood, WI
- Tractor
- MF1754 HST, Cab, 6 foot Front Mount Snowblower
They work the same way a light bulb filament works, but in slow motion.
When you supply 110 volts to a light bulb, there is an inrush of current thru the filament. There is unlimited amperage available, but as soon as the filament gets (white) hot, (micro-seconds) resistance builds and restricts how much current can flow thru the filiment. If it were not for this resistance, the filament would burn out, instantly.
Heat tape is designed so that the cooler the tape, the more current it conducts. When it gets hotter, resistance increases and less current flows. It self regulates, just like the light bulb, but much slower.
If I understand YOUR theory correctly, a frost plug element self regulates.
Why doesn't it just get warm (hot) and then restrict its current to a sustainable level?
Why does it burn out if not immersed?
Why does immersing it in water change anything?
When you supply 110 volts to a light bulb, there is an inrush of current thru the filament. There is unlimited amperage available, but as soon as the filament gets (white) hot, (micro-seconds) resistance builds and restricts how much current can flow thru the filiment. If it were not for this resistance, the filament would burn out, instantly.
Heat tape is designed so that the cooler the tape, the more current it conducts. When it gets hotter, resistance increases and less current flows. It self regulates, just like the light bulb, but much slower.
If I understand YOUR theory correctly, a frost plug element self regulates.
Why doesn't it just get warm (hot) and then restrict its current to a sustainable level?
Why does it burn out if not immersed?
Why does immersing it in water change anything?