Page 202 - Electromechanical Devices and Components Illustrated Sourcebook

164 Electromechanical Devices & Components Illustrated Sourcebook

Cable Clamp

Male Female

Panel
Wall Figure 9-57 Turn-Lock AC Connector

Automotive Connectors

Within the automotive community there are three common
connectors used. These are the barrel, flat or “spade,” and
Cable hook or “twist lock” connectors. All three of these connectors
seem to perform well in the harsh automotive environment.
Figure 9-55 Standard 220-VAC Connectors
The barrel connector is simply a cylinder-shaped plug and
matching barrel. The barrel is split and spring-loaded closed.
The plug has a tapered nose and a locking groove. When the
Most 240 volt power is used for major appliances such as
plug is pushed into the barrel it springs open and a detent
stoves, dryers, hot water heaters, home welding machines,
snaps into the locking groove. Figure 9-58 shows a crimp-on
and the like. These units use higher current receptacles, as
barrel connector.
shown in Figure 9-56. Receptacles in this size range can have
current ratings anywhere between 25 to 100 amps.
Plug Jack
Figure 9-58 Barrel Connector

Receptacle Flat, or “spade,” connectors consist of a flat male plug and
a formed female receptacle. The receptacle has the edges
rolled in a fashion that pinches the outer edges of the male
plug when it is inserted. These connectors are available in
uninsulated versions, as shown in Figure 9-59, as well as fully
insulated configurations.

Plug

Male Female
Figure 9-56 High-Current 220-VAC Connector
Figure 9-59 Flat or Spade Connectors

Turn lock AC connectors, as shown in Figure 9-57, are
commonly used in environments where accidental disconnec- Turn-lock, or hook, connectors form an exceptionally solid
tion is a possibility. To mate, the two connectors are pushed connection. They are ideal for permanent and semipermanent
together and twisted in their locked position. These connec- applications. They are not insulated and require wrapping with
tors are often used in manufacturing facilities where electrical electrical tape or heat shrink after connection. Figure 9-60
power tools are used at the end of a long extension cord. The shows a typical turn-lock connector.
locking action prevents the connectors from being pulled
apart when the cord is pulled by a worker. Another attribute is
that the connector is nonstandard, which means that a power Terminal Strips
tool with a twist lock connector can only be used at a facility
that has matching receptacles. This feature greatly reduces Terminal strips are the preferred connection for permanently
equipment theft because the tool can’t be used anywhere else wired subassemblies and controls within an electromechani-
and a pawn shop won’t pay any thing for a tool with an odd cal system. Terminal strips are offered in a wide variety of
connector. designs, configurations, and terminal counts.