Application Note 57

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APPLICATION NOTE NO. 57

Connector Care and Cable Installation
Revised August 2007

The Application Note describes the proper care and of connectors for Sea-Bird instruments with standard (Impulse XSG/AG) bulkhead connectors. The Application Note is divided into three sections:

Connector Cleaning and Inspection, and Cable / Dummy Plug Installation

Clean and inspect connectors, cables, and dummy plugs:

Before every cruise.
During the cruise -- This is a good practice if you have a few days of down time between casts.
After every cruise -- This is the best way to find and remove any corrosion on connector pins before severe corrosion develops.
As part of your yearly equipment maintenance.

Follow this procedure:

Carefully clean the bulkhead connector and the inside of the mating cable's boot or the dummy plug with a Kim wipe. Remove all grease, hair, dirt, and other contamination.

Clean bulkhead connector

Clean inside of cable boot or dummy plug

Inspect the connector and cable boot or dummy plug:

Inspect the pins on the bulkhead connector for signs of corrosion. The pins should be bright and shiny, with no discoloration. If the pins are discolored or corroded, clean with alcohol and a Q-tip.

Inspect the bulkhead connector for chips, cracks, or other flaws that may compromise the seal.

Inspect the cable boot or dummy plug for cuts, nicks, breaks, or other problems that may compromise the seal.

Replace severely corroded or otherwise damaged connectors, cables, and dummy plugs -- contact Sea-Bird for instructions and a Return Material Authorization (RMA) number.

Corroded pins on bulkhead connectors -- Connector on right has a missing pin

Using a tube of 100% silicone grease (Dow DC-4 or equivalent), grease the bulkhead connector and the cable boot or dummy plug:
CAUTION: Do not use WD-40 or other petroleum-based lubricants, as they will damage the connectors.

100% silicone grease

Squeeze the silicone grease -- approximately half the size of a pea -- onto the end of your finger. Apply a light, even coating of grease to the molded ridge around the base of the bulkhead connector. The ridge looks like an O-ring molded into the bulkhead connector base and fits into the groove of the mating cable boot or dummy plug.

Apply grease to molded ridge

Squeeze the silicone grease -- approximately half the size of a pea -- onto the end of your finger. Apply a light, even coating of grease to the inside of the cable boot or dummy plug.

Apply grease to inside of cable boot / dummy plug

Align the bump on the cable boot or dummy plug with the large pin on the bulkhead connector, and align the sockets with the pins. Do not twist the cable boot or dummy plug on the bulkhead connector. Twisting can lead to bent pins, which will soon break.

Push the cable boot or dummy plug all the way onto the bulkhead connector. There may be an audible pop, which is good. With some newer cables or dummy plugs, or in cold weather, there may not be an initial audible pop.

After the cable or dummy plug is mated, run your fingers along the cable boot or dummy toward the bulkhead, milking any trapped air out of the boot or plug. You should hear the air being ejected.

CAUTION: Failure to eject the trapped air will result in the connector leaking.

Locking Sleeve Installation

After the cable boot or dummy plug is mated to the bulkhead connector, install the locking sleeve. The locking sleeve secures the cable or dummy plug to the bulkhead connector and prevents it from being inadvertently removed. Important points regarding locking sleeves:

Tighten the locking sleeve by hand. DO NOT use a wrench or pliers to tighten the locking sleeve. Over-tightening will gall the threads, which can bind the locking sleeve to the bulkhead connector. Attempting to remove a tightly bound locking sleeve may instead result in the bulkhead connector actually unthreading from the end cap. A loose bulkhead connector will lead to a flooded instrument. Pay particular attention when removing a locking sleeve to ensure the bulkhead connector is not loosened.
It is a common misconception that the locking sleeve provides watertight integrity. It does not, and continued re-tightening of the locking sleeve will not fix a leaking connector.
As part of routine maintenance at the end of a day's casts, remove the locking sleeve, slide it up the cable, and rinse the connection (still mated) with fresh water. This will prevent premature cable failure.

Cold Weather Tips

In cold weather, the cable or dummy plug may be hard to install and remove.

Removing a frozen cable boot or dummy plug:

Wrap the cable boot or dummy plug with a washrag or other cloth.
Pour hot water on the cloth and let the it sit for a minute or two. The cable boot or dummy plug should thaw and become flexible enough to be removed.

Installing a cable or dummy plug:

When possible, install cables and dummy plugs in warm environments. If not, warm the cable boot or dummy plug sufficiently so it is flexible. A flexible cable boot or dummy plug will install properly.

Note about Alternative Connectors:

As an option, Sea-Bird offers wet-pluggable (MCBH) connectors in place of the standard Impulse XSG/AG connectors described in this application note. Wet-pluggable connectors have a non-conducting guide pin to assist pin alignment and require less force to mate, making them easier to mate reliably under dark or cold conditions, compared to our standard connectors. Wet-pluggable connectors may be mated in wet conditions; their pins do not need to be dried before mating. By design, water on the connector pins is forced out as the connector is mated. However, they must not be mated or un-mated while submerged. Like standard connectors, wet-pluggables need proper lubrication and require care during use to avoid trapping water in sockets. If desired, Sea-Bird can retrofit your existing instruments with wet-pluggable connectors; contact Sea-Bird for pricing information.

Last modified: 05 Dec 2007

Sea-Bird Home Phone: (+1) 425-643-9866 Fax: (+1) 425-643-9954 E-mail: seabird@seabird.com