Potentiometer input, 25 or 35
amp, 3 phase din rail power controller
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Features
- Allows a customer to dial in a
request from 0% to 100% power.
- Accepts a standard potentiometer
input and provides a high speed, time proportional AC
output (TPO). That is a zero-crossing, "no electronic noise", power
control signal that is ideal for resistive heaters, heat sealing bars,
injection molding nozzle zones, simple cookers, etc.
- Output cycle time ("ON" time +
"OFF" time) = approximately 0.5 second at 50%. Output resolution is one half of
one sinewave (8.3 msec for 60 hz applications).
Note: Rapid pulsing of the heaters
provides the most precise temperature control, PLUS it dramatically increases
the life of the heaters due to a reduction in the thermal stress of expansion
and contraction.
- A standard 0-5k potentiometer
can be mounted anywhere on the machine.
- Any standard 24 volt DC power
supply can be used, such as your existing PLC power supply.
- A 680 ohm, 5%, 1/2 watt resistor
is installed in series.
- A 6.8k ohm, resistor is
installed in parallel.
- A green LED shows input status
on the power controller
- Zero crossing activation -- low
EMI, low noise to nearby electronics
- Available for the DMA3-6V75T,
three phase solid state contactor
- UL, CSA, CE
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Three phase, 25 or 35 amps per leg, din
rail contactor
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Features
- Maximum Surge Survival™
technology -- triple layer, voltage surge protection
- Green LED for input
status
- Thermally optimized heat sink
permits edge-to-edge installations on a din rail
- Built-in snubber
circuit
- Zero crossing activation -- low
EMI, low noise to nearby electronics
- Internal 50A thyristors for high
inrush capability
- 4000 volt isolation, 1400Vpk
blocking voltage
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- 1000 volt / microsecond
immunity
- Highest thermal efficiency --
less than 1.2 watts per amp switched, per leg
- CE, UL recognized, CSA
- Industry standard A1, A2, L1,
T1, L2, T2, L3, T3 terminal numbers
- High density design permits more
amps per square inch
- 3Ø = 25 amps per leg,
2Ø using L1/T1 and L3/T3 = 35 amps per leg.
- Optional: 3 internal MOVs for a
fourth layer of surge survival
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Part
Numbers
Customer to supply the 0-5k pot,
resistors, and 24 VDC power supply.
DMA3-6V75T up to 75 amps TOTAL; 25A on three
legs or 35A on 2 legs; 660V max, 4-20mA analog input activated 
DMA3-5V75T up to 75 amps TOTAL; 25A on three
legs or 35A on 2 legs; 575V max; 3 internal MOVs; 4-20mA analog input
activated. Non-standard model -- consult factory for price and availability.
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Specifications
| Part
Number |
Line Voltage
Range (VAC) |
Load Current Range (A
RMS) |
|
Max Voltage Drop @
20mA |
|
| |
| 4-20mA analog input activated |
| DMA3-6V75T |
24-660 |
.10-25 (3 leg) or 35 (2
leg) |
|
10 VDC |
|
| DMA3-5V75T |
24-575 |
.10-25 (3 leg) or 35 (2
leg) |
|
10 VDC |
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| Installation |
The
DMA3 can be installed on a din rail or directly on a metal panel. The heat sink
must be installed so the air flows up and through the fins. |
| Off-State
dv/dt |
1000
v/µs |
| Isolation |
4000
volts isolation |
| I²T fuse
|
50A
or less, for example: Bussman FWP50A14F, FWC32A10F, FWC20A10F. Ferraz Shawmut
B093910, M330015, K330013 |
| Example of
control |
0% =
heater or load is "off"
50% = heater "on" 250 mseconds, "off" 250 msec, "on"
250 msec...
75% = "on" 375 msec, "off" 125msec, "on" 375 msec....
85% =
"on" 425 msec, "off" 75msec, "on" 425 msec....
100% = heater "on"
Since the contactor is switching at
the zero crossing mark of a sinewave, there is no electrical noise that might
interfere with nearby electronics. Also, since the calculated ON or OFF time
period is measured in half sine waves, the contactor will automatically adjust
the total cycle time in order to maintain the best ratio of ON/OFF to match
your control input. |
| Turn-on
time |
<8.3 ms at 60hz |
| Turn-off
time |
<8.3 ms at 60hz |
| Power
terminals |
Will
accept #24-#10 AWG wire. Torque: 7-9 inch lbs. |
| Control
terminals |
Will
accept #24-#14 AWG wire. Torque: 4 inch lbs. |
| Internal
MOVs |
The
"5V" models have three internal MOVs installed providing a fourth layer of
surge survivial. Using the MOVs limits the product to applications from 48 -
575 volts. |
| Terminology |
The
word "leg" refers to a switched AC power line. A three phase application may
use 3 switched lines or 2 switched lines. |
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