speed controler

[m_c]

ptwj's calc is correct for the starting current.
Power = Current x Voltage, and to get Voltage drop across the resistor, we use Voltage = Current x Resistance

To get Voltage over the resistor, we use Voltage = Current x Resistance, which is 17A x 0.18 = 3.06V
Power = 17A x 3.06v = 52.02W.
For running at the continuous rating, 0.85A x 0.18 = 0.153V x 0.85A = 0.13W
For running at the intermittent rating, 1.75A x 0.18 = 0.315V x 1.75A = 0.551W
For startup.......................................17A x 0.18 = 3.06V x 17A = 52.02W

However, that is the instantaneous power consumption at switch on at full power. The KBIC should slowly ramp up to the set power, to avoid any major inrush issues.

should i have continuity across motor + motor - coz i have ? dont think thats right

What do you mean across Motor + Motor?
On the board, or the motor itself?