DC twin core hot water element 1.0 or 0.8 Ohm
DC twin core hot water element 1.0 or 0.8 Ohm
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These twin core water elements can be used on 12, 24 and 48V battery systems to divert surplus power to a water tank.  They have a 1 ¼” BSP boss, are 400mm long and are made from stainless steel.

Choose resistance from the drop-down menu.

  • 1.0 Ohm pair can be wired as 2.0, 1.0 or 0.5 Ohm
  • 0.8 Ohm pair can be wired as 1.6, 0.8 or 0.4 Ohm

The power dissipated in a resistor is calculated as follows:

  • (fully charged battery voltage)^2 / resistance

For example a 1 ohm resistor on a 12V battery will dissipate 14x14/1 = 196W because it will reach 14 volts.

Also check that the maximum current draw does not exceed 30 amps or you may overload your SSR.

Current =  Power/fully charged battery voltage.

It is unlikely that your thermostat (if any) will be able to work with the DC current.

Power (Watts)
Ohms 14V 28V 56V
0.40 490 1960 n/a
0.50 392 1568 n/a
0.80 245 980 n/a
1.00 196 784 n/a
1.60 123 490 1960
2.00 98 392 1568

 

On DC water elements good practice is to ensure:

  • Termination points are tight
  • No insulation or combustible material near element connections
  • Terminal cover is metal to reduce any fire risk from an arching connections
  • Check all dc connections annually for any sign of heat damage & rectify
  • Consider the implications if the water tank boils
  • Ensure element has water cover at all times
  • Clearly label how element is to be turned off 
  • Comply with local wiring rules

Refer to PowerSpout Document Index Links for a complete index of documents.

Refer to PS MPPT DC water heater installation Guide June 16  for install instructions.