A precise and accurate electrical cable integrity monitoring for ungrounded/floating electrical systems


Line Insulation resistance monitoring is an industry accepted and recognised method of measuring the effects of water ingress into and around the umbilical electrical conductors. Electrical integrity monitoring is usually included on the topside facility at the input to the umbilical electrical conductors.

It is important to be able to monitor the integrity of the electrical conductors from when they are first installed. Degradation trending needs to be possible independently of the actual IR. Accuracy and repeat-ability of the sensing solution is key.


With its precise and accurate measurements of Insulation resistance, Capacitance and other advanced electrical parameters, V-LIM not only provides a better picture of the health of the system over time, but also provides opportunities to identify problems before they arise. This allows proactive and more cost effective intervention to be undertaken based on risk and asset condition assessments rather than relying on reaction to failures after they have occurred.

The V-LIM unit employs Digital Signal Processing techniques which facilitate trending and characterisation of the system condition with reliable fault disclosure over a wide measurement range. V-LIM is fully compatible with power transmission, communications as well as combined communications on powerline systems and is easily integrated into existing or new infrastructure via its convenient panel mounting arrangement.

Additionally, V-LIM is V-LIFE ready - an exclusive feature for subsea applications which can be activated to increase the system IR and availability without the need for costly intervention or risk of introducing new faults.

Key Benefits

  • Continuous monitoring provides real-time trending.
  • When combined with Viper Subsea's LIMBO analysis time to failure predictions can be made.
  • Interface modules allow for easy replacement of legacy equipment.
  • Determine fault locations when combined with the use of the V-SLIM and V-NET systems.
  • Compatible with V-LIFE technology.

Key facts

  • Two separately configurable alarms with associated relay contacts to take desired action
  • Timestamped measurement data is logged to internal memory
  • Touchscreen LCD and web interface displays
  • Ethernet, RS485 Modbus and 4-20mA interfaces
  • Upload firmware and configuration settings from front panel USB interfaces via memory stick or service PC
  • Download data log to memory stick or service PC
  • Compatible with temporary application of external IR test unit without physical disconnection of V-LIM
  • Multiple user security levels supported for secure access
  • Built-in self-test