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Phase/AMP Series DPA1/DCPA1
1-8.
OPTION A, CURRENT LIMIT.
1-9.
The Current Limit provides feedback to the summing point of an operational amplified to hold thyristor
current output to a preset limit. This limit is continuously adjustable between 25 percent and 125 percent of the
full rated current output. With this option, the output current can be regulated (limited) to within 5 percent with
a loan conductance change of 100 percent. This option is used when the load becomes excessive during
some portion of the operating cycle. The Current Limit option includes a RMS Current Indicator (refer to
Option C, paragraph 1-10) to measure and display the output current. A Current Transformer (refer to Option
D, paragraph 1-12) is required but not supplied with Option A.
1-10.
OPTION C, RMS CURRENT INDICATOR.
1-11.
The Current Indicator is part of the Current Limit (option A, refer to paragraph 1-8), however, it can be
purchased separately. The indicator is a 0 to 5 ampere AC ammeter. A Current transformer (option D, refer to
paragraph 1-12) is used to set the range of the indicator. The function of the Current Indicator is to measure
and display the RMS current output to the load. The accuracy of the indicator is (+5) percent of full scale
definition.
1-12.
OPTION D, CURRENT TRANSFORMER.
1-13.
The Current Transformer is designed for use with the Current Limit (option A, refer to paragraph 1-8)
or Current Limit, Fast Gate Shutdown (option F, refer to paragraph 1-16). The function of the transformer is to
provide the proper turns ratio to match the current range of the Current Indicator (option C, refer to paragraph
1-10) to the current output range of the DPA-1. Normally, a 2VA transformer is supplied, but if the Current
Indicator is to be remote, a 5VA transformer is required and is designated option X.
1-14.
OPTION E, HEAT SINK THERMOSTAT.
1-15.
The Heat Sink Thermostat is recommended for use with water cooled or fan cooled units. This option
consists of a thermally actuated relay that provides a contact closure in the even of a heat sink over-
temperature condition. The over-temperature condition may be caused by an over current condition, a failure
of he cooling system, or by abnormally high ambient temperatures. The relay contacts are fully insulated from
the heat sinks. It is available with either N.O. or N.C. contacts as specified by purchase order.
1-16.
OPTION F, CURRENT LIMIT, FAST GATE SHUTDOWN AND AMMETER.
1-17.
The description of the current limit portion of option F is identical to the description of the Current Limit
(option A) provided in paragraph 1-8. The fast gate shutdown portion of option F shuts down the unit within
one cycle after the peak output current exceeds a pre-set level. The pre-set level is continuously adjustable
between 25 percent and 300 percent of the full rated output current of the Unit. This option is recommended in
applications where surge currents are quite common and repetitive clearing of fuses would be an expensive
nuisance.
1-18.
OPTIONS G, H, AND N, ENCLOSURES.
1-19.
All types of JIC and NEMA enclosures are available for the DPA-1 PHASE/AMPS. Option G relates to
enclosures containing fans, air filters, and transformers. Option H related to louvered enclosures and option N
relates to expanded metal enclosures. Special machining, etc. required for any particular installation can be
accomplished prior to shipment and in accordance with user's specifications.
1-20.
OPTION Q, POWER FEEDBACK AND CURRENT LIMIT MODULE.
1-21.
Power feedback is used when it is desired to put constant power into a load over a wide range of load
conductance. The current limit portion is included to avoid operation that would result in excessive currents at
low Voltages even though the load power rating is not exceeded.
Transformer. A Percent Power Indicator (option T, refer to paragraph 1-22) is also available.
Document 9100030
AMETEK HDR Power Systems
This option requires a 5VA Current
Description
3
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