Live relationshipRT=R1+R2R_T = R_1 + R_2
Current splitter. Second resistor at 270 Ω. Loop resistance 450 Ω, Safe resistance 320 Ω. Currently loop resistance is over by 130 Ω.CURRENT SPLITTERTUNINGSOURCELOOP RESISTANCESAFE RESISTANCE270 Ω

Loop resistance

450Ω

Safe resistance

320Ω

270 Ω

Current splitter. Second resistor at 270 Ω. Loop resistance 450 Ω, Safe resistance 320 Ω. Currently loop resistance is over by 130 Ω.

Narrative feed

You are called to a signal repeater that keeps burning out its driver.

The driver survives only if the loop presents 320 Ω. One fixed resistor gives 180 Ω. The second is set wrong.