Page 194 - The ROV Manual - A User Guide for Remotely Operated Vehicles 2nd edition

Epoxy connectors are a good choice for medium depth. Their greatest weakness is to side load- ing. A means of protecting the cable (attached to the epoxy connector) from being pulled, espe- cially against side loads, is an important consideration. This may be as simple as black taping it to the ROV frame.
Electrical contacts are selected for power, considering the anticipated voltage and current requirements. The mechanical design should prevent the engagement of the pin and socket before the keykeyway engages. Sharp interior edges, such as on a keyway, should be recessed from any radial O-rings. Contacts passing through epoxy bulkhead connectors must be primed to assure good bonding for open face pressure.
Weaknesses in epoxy connectors include susceptibility to damage from side loads, flammability in the event of high-voltage shorting of pins, and exposed contacts inside the female receptacle. Water retained behind the radial seal of the male connector plug when vertical can drip onto the exposed pins as the plug is retracted.
8.5 COTS underwater connectors
Commercial-off-the-shelf (COTS) underwater connectors come in a wide variety of standard con- figurations for both electrical and fiber-optic conductors. These “standards” can be classified into the following generic categories:
Rubber-molded connectors
These are molded, typically in Neoprene, in a number of different configurations including straight, right angle, miniature, and others. They can be capable of high pressures and are typically low cost. They can be cleanly and inexpensively molded onto jacketed cables and are easy to use.
One of the oldest rubber-molded connector designs is known by the initials of its original manu- facturer, Electro-Oceanic. EO connectors (Figure 8.30) are available from several manufacturers with 28 contacts and are rated to 10,000 psi (690 bar) or more. Electrical rating per contact is 115 V/6.5 A or 230 V/15 A.
A vent hole to the exterior in the electrical socket allows EO connectors to be mated or unmated at any depth, though not with power on. The male pins each have two circular contact bands on them. The male pins are flared at the tip and oversized to the inside diameter of the female socket. This insures a wiping action and positive seal by forcing water through the length of the female socket and out the vent.
SubConns (manufactured by SubConn), Wet Cons (manufactured by SeaCon), or Wet Pluggables (manufactured by Teledyne Impulse) are among the most popular types of rubber-molded connectors (Figure 8.31). These are available with 125 contacts. The female receptacles have one or more rings molded into them that seal to the pins on the mating plug. Keep in mind, the more contacts, the more force required for mate/demate. Also, as the number of contacts increase, the outer pins are more sus- ceptible to demating (loss of electrical connection) should the connector experience side loading. Variations of these connectors have been used to ocean trench depths.
Epoxy-molded connectors
Rigid epoxy compounds add greater strength and dimensional control to molded connectors. These assemblies perform well at pressure and are moderately low priced. Some still call this style
8.5 COTS underwater connectors 183