Deluxe Model 
for Variable Trip, Hysteresis & Delay Setting with Differential Input



  • Adjustable trip point.
  • Adjustable hysteresis.
  • Adjustable delay on turn off or turn on. Typical 0-2 seconds.
  • Differential input (difference of two voltages floating about a common voltage).
  • Trip point may be set for a negative, zero, positive, or AC voltage.
  • Hysteresis may be set for any value within voltage range.

Delay on turn off or on (SPDT output) may be set for zero to minutes.

Power line isolation. Sense voltage common may be off ground by up to 1,000V DC.

Power source: 
5 or 12 or 24V DC. 
115, 208 or 230 Volt, 50/60Hz (specify) Non-isolated commons or isolated commons for power neutral and sense inputs. 

Output, isolated mechanical relay. NC and NO contacts.
8 amps 250V AC
8 amps 30V DC

Internal input trip range: specify on order, ±1 Volt AC PK to +200 Volt into 1M.

0 to 127V AC
0 to 100V DC
-10 to -5V DC
-5 to +5V DC
Any higher voltage with external resistor.

Maximum allowable continuous sensor input current: 0.7mA into 1M basic input to develop ±, AC PK 1V to 200V.

Internal trip input resistance: 1M.

Hysteresis: min. trip to max. turn on. Specify on order.
Typical range: 0 to 2 volt DC decrease to 40% of basic internal trip.

Set point repeatability 1% AC. 0.1% DC.

Temperature range -10°C to +55°C.

Basic reset time 100 milliseconds.
Over-voltage withstand 200V to 2500V, depending on model.


  1. Select internal resistance of R1 and R2 for desired operating range.
  2. To trip off AC line connect 1 to 4, 2 to 3, 4 to 5 and set function switch to AC.
  3. IIf higher than 200V add external HV resistor to develop 1V to 200V, 0.7mA max across 1M input resistor R1 or R2.

    (Pin out & Block wiring diagram)

 Standard Model

Deluxe Model

Specifications are for reference only and are subject to change.
Contact Ross Engineering Corp. for current information.