Red Jacket® ISOTROL™ Control Box

The Red Jacket® ISOTROL™ 1-8 Control Box is the most versatile dispenser handle signal isolation system available. It provides a means to remove all external voltage sources, including feedback, during periods of maintenance and service of the dispensing equipment to meet NEC requirements.

The Red Jacket® ISOTROL™ 1-8 Control Box isolates handle signals between each dispenser and protects against wiring shorts and phasing issues. It is available with or without a built-in 30-amp 2HP rated relay.

  • ISOTROL™ 1-8 units without the relay are designed for use with the TLS-450PLUS or another component for motor control – IQ, standard control box or three phase magnetic starter and will accept up to eight individual dispenser signals.

  • ISOTROL™ 1-8R units with the relay bypass an ATG to activate one pump and will accept up to eight individual dispenser signals. They can also be utilized to activate a second pump in manifolded applications.

Each configuration also has a 240VAC international equivalent – ISOTROL™ 1-8-i and ISOTROL™ 1-8Ri. Please contact customer service for more information.

Did you know? 

The ISOTROL™ 1-8 provides electrical isolation between the dispenser pump enable signal and the submersible turbine pump control relay. Other energized sources of power can still exist within the dispenser even with this device installed. You should always verify that all sources of power are disconnected before servicing a dispenser. Always follow proper Lockout/Tagout procedures when servicing electrical equipment.

At any time the enclosure must be opened during a troubleshooting procedure, disconnect controller power prior to removal of the cover. This includes the dispenser signal outputs that are powered from separate circuits in the system.

Product Form

Part Number




ISOTROL™ Control Box 120v w/ relay



ISOTROL™ Control Box 120v w/o relay



Features and Benefits

  • Isolates the handle signals between each dispenser.

  • Isolates and protects individual dispensers from wiring shorts or phasing issues.

  • Isolates and protects technicians from dangerous feedback during service.

  • Ready interface with the Red Jacket® IQ Control Box and/or the TLS-450PLUS.

  • Compliant with NEC requirements for handle isolation.

  • Accepts up to eight individual dispenser signals.

  • If ordered without relay, it must be used with another component for motor control.

  • Dedicated Automatic Tank Gauge (ATG) line leak output and coil for easy compatibility with Pressurized Line Leak Detection (PLLD).

  • Terminals are labeled for easy wiring and compatibility.

  • May be used with all Red Jacket and competitive submersible turbine pumps.

  • Easily retrofitted to existing locations.



Type 1 enclosure, 6”x6”x4”

DISP Inputs

10 mA @120V or 240V 50/60 Hz

Control Circuit

15 mA @ 120V 50/60 Hz or 240V 50/60 Hz

ATG Output

750 mA @ 120V or 240V 50/60 Hz

Control Relay

30A DPST 120/240VAC 50/60 Hz



14-28 AWG

10-18 AWG Main