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Phase/AMP Series DPA1/DCPA1
SECTION II - INSTALLATION
2-1.
ENVIRONMENTAL CONSIDERATIONS.
2-2.
Prior to installing the equipment, some consideration should be given to the factors of temperature,
vibration, and contamination. These factors are discussed in paragraphs 2-3 through 2-8.
2-3.
TEMPERATURE
2-4.
Ambient temperature should be a major consideration in selecting a suitable mounting location for the
DPA-1. While a thermal safety margin is an inherent feature of this unit, ambient temperatures in the vicinity of
the SCR heat sinks should not exceed 122°F (50°C) without appropriate de-rating of the power output
capability of the unit.
temperature should in no case be allowed to exceed 158°F (70°C). When convection cooling is used, the
DPA-1 should be mounted upright with heat sink fins oriented vertically relative to the ground plane. This will
maximize the dissipation of heat. If the unit is to be mounted in an enclosure, it may be necessary to supply
outside air for cooling.
2-5.
CONTAMINATION.
2-6.
In areas where conductive dust or other foreign matter is likely to accumulate in an exposed DPA-1, an
enclosure should be obtained to cover the unit. This measure necessitates the use of a fan and air filter, clean
air supply, or a water supply (where water cooled heat sinks are used). JIC and NEMA enclosure for any
specific installation, are available. Refer to paragraph 1-18.
2-7.
VIBRATION
2-8.
The DPA-1 PHASE/AMP can sustain pitched vibration of small amplitude safely. Environments with a
significant degree of pitched or un-pitched vibration should be avoided. Standard shock mounting techniques
are recommended for DPA-1 if it is to be subjected to significant vibration pick-up.
2-9.
POWER LINE CONSIDERATIONS.
2-10.
When an SCR fires into a purely resistive load, full current will attempt to flow instantaneously. If a
power source with a large amount of inductance in the transformer and/or the power lines is feeding the
SCR's, the inductance will limit the rate at which the load current may rise from zero to maximum.
Consequently, at the instant of SCR firing, current through the load and SCR's will be zero. Correspondingly,
the line Voltage at the SCR's will drop sharply to zero. Recovery time is proportional to the L/R ratio (L is the
power source plus line inductance and R is the combined line and load resistance) of the system, and is
usually approximately one millisecond. The result of this sequence of events is the introduction of a "notch" or
inverted spike into the Voltage waveform which will generate noise up and down the power line supplying the
SCR's. This may, in turn, cause interference in other electrical or electronic equipment sharing the same line if
such equipment is not designed to reject the noise. Other PHASE/AMPS on the same line will not be affected.
The noise will not be transmitted back through any transformers or to any other windings on the same
transformer.
Document 9100030
De-rating data for any particular model is available upon request.
AMETEK HDR Power Systems
Installation
The ambient
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