Multiple Channel Wet-Mateable Electro-Optical Connectors: Qualification Testing
Authors: Barlow Stewart M. 
Published: October 2008

Abstract
Ocean Design, Inc. (ODI) has developed a wet-mate able connector which, in the configuration tested, passes foursingle-mode optical circuits and four 10 amp electrical circuits. The connector is presently built in diver-mate, stab plate and ROV configurations. This paper summarizes the esults of qualification tests of these connectors conducted in collaboration with Kvaerner FSSL, Ltd. (KFL). Qualification tests included high and low temperature, thermal shock, hydrostatic pressure, mating and debating in sandy, salty seawater both at 1 atmosphere and at 6,00Opsi, mechanical shock, vibration and others. In addition to these qualification tests, an integration test in a mock-up of the customer's hardware was completed. Typical pass-fail criteria were 0.5dB optical loss @ 1,550nm on the optical circuits, and 1 gig ohm isolation resistance @ 500 VDC on the electrical circuits. Details of the testing and the subsequent results will be discussed.

Introduction
Over the past 2 years, OD1 has designed and developed a range of multiple channel wet-mate able electro-optical connectors. These connectors are a novel and unique product which provides enabling technology for the use of fiber-optics in the sub sea environment. An essential part of this development was the qualification of the connector for the often harsh life of sub sea use. ODI, together with KFL, conducted a significant qualification test program on the connector. This testing included all of the tests normally came out on wet-mate able electrical connectors, with the addition of optical performance tests. KFL are a sub sea control system supplier for the Oil & Gas industry, and their ultimate use for the connector will be in their optical sub sea communications system (Ref. 1). The testing has also been included as part of an EC THERMIE program that KFL are conducting, with the objective of demonstrating that fiber optic communication is a feasible and reliable alternative to contemporary electrical sub sea communications. Norsk Hydro and TOTAL were involved in the program, and both attended some of the qualification tests at ODI's facility in Florida, USA. In addition to the testing came out at ODI's facility, "real-life" tests were conducted in a dock trial, again in conjunction with KFL. Details of the individual tests follow, together with a summary of the results, and these are compared to the connector's requirements. A brief discussion of actual and potential uses for the connector is also included.

The Connector Under Test
OD1 developed a fully wet-mate able, multiple channel, electro-optical connector with up to eight optical or electrical circuits. The optical circuits are available as either single- ormulti-mode with a typical loss of less than 0.5dB. The electrical circuits are rated at 10 amps and 500 VDC. The connector is designed to be fully wet-mate able at any ocean depth and supports differential pressure of up to 6,000psi. In both connector halves, the contacts are contained within oil filled, pressure balanced chambers. As the connectors are mated, rolling seals on the mating faces of the respective connector halves squeeze together to displace any water between them. Further mating causes the seals to rotate, and displace any debris trapped between them.