OPERATION
In operation, the instrument power cord is connected directly to the
power outlet of the model 185. The Power Safety Delay, in turn, is connected
to a suitable electrical outlet. After connections have been made, the
operator simply depresses the Reset Switch and full power is now available
to the protected instrument. Should there be an electrical power failure,
all units, including the Power Safety Delay, are deactivated. Upon resumption
of electrical power only the Power Safety Delay will be reactivated and
will indicate that there has been a power failure by its Failure indicator
light. To apply power once again to the equipment the operator has but
to depress the Reset Switch. This delay has permitted the operator to alter
the start-up parameters to his own satisfaction before restoring the equipment
to active status.
APPLICATION
Not infrequently, power failures occur when operators are not present.
Evenings, weekends and holidays can often present opportunities for undue
hardship on that equipment which can be damaged by power failures.
Instrumentation
with reactive gas-heat combinations is particularly prone unless protected
in a manner other than fusing. Low Temperature ashers used with Oxygen
or other gases should be used in conjunction with a Power Safety Delay,
as well as other vacuum systems. Gas chromatographs with dissimilar heat
zones and dissimilar heating rates for these zones can be damaged, e.g.;
detectors and valving in chromatographs heat much more slowly than column
ovens and serve as dumps for column bleed for a long interval before they
reach operating temperature. This can be an expensive exercise, especially
with detectors such as the Ni-63 electron capture detectors, flame photometric
detectors, microcoulometric detectors and others.
In some sophisticated electronic equipment there is a particular sequence
which should be followed when applying power prior to full operation. Should
there be a power failure during operation without the Power Safety Delay,
full power would be applied without benefit of the proper sequence. The
model 185 assures control of the re-starting of the equipment since power
would be delayed until the operator had re-established the proper parameters
and applied power via the Reset Switch.
SAFETY
The model 185 Power Safety Delay has particular application to those
situations where personal safety is affected by electrical power failures.
Hydrogen generators, when used with hydrogen consuming equipment, should
be operated through a Power Safety Delay. This is particularly true for
equipment which has its own automatic hydrogen shut-off in the event of
power failure. Once power is resumed the hydrogen flows into the consuming
unit but is not consumed since the flame would have been extinguished through
the automatic shut-off. Instead, hydrogen enters the work environment freely,
presenting a hazard to personnel. This is of great concern in confined
areas, such as environmental chambers, remote monitoring vans, etc.
REMOTE CONTROL
AADCO offers a special model of the Power Safety Delay, the model 187,
for remote protection and re-activation. In this unit, when a power failure
occurs and then power resumes, the Failure indicator light will so indicate
as with the model 185. However, simultaneously a signal will be presented
to a special 2-conductor connector on the face of the unit for relay to
a remote monitor. After ascertaining that instrument conditions warrant
resumption of power to the equipment, reactivation is accomplished remotely
through a second 2-conductor connector.
SPECIFICATIONS:
Size:
6" ? x 4" x 2 ?"
Weight:
2 lb
Power:
Max.
25 amps @ 115V.
