The PDA1500 High VAC/VDC to Logic Level Converter is an easy to use DIN rail mounted device for converting high voltage signals into logic level signals for use as a digital input to a wide range of process control and display equipment.

The PDA1500 accepts up to four high voltage AC or DC signals. The PDA1500-115's inputs accept 85-130 VAC or VDC, and the PDA1500-230's inputs accept 185-265 VAC or VDC. Powered from 12-24 VDC, the PDA1500 can drive outputs even when no high voltage inputs are present. The outputs are user selectable for high or low states when voltage is present at the inputs.

Cascade mode is ideal for monitoring signals that can result in cascading or subsequent failures. This mode monitors the point of failure when a failure in a single input causes a failure in all alarm points in a "series" system.

The PDA1500 is mounted in an ABS plastic DIN rail mounted enclosure for easy mounting inside a panel or instrument enclosure.

Features

  • Combine with the Vigilante II Annunciator to Monitor High Voltages
  • Four High Voltage Inputs Up to 265 VAC or VDC
  • Four Digital 5 VDC Outputs
  • Easy DIN Rail Mounting
  • Simple Two-Button Setup
  • Cascade Mode for Series Break Configurations
  • Multi-Unit Cascade Mode

General

Configuration Method: Two latching pushbuttons for selection of output state inversion and cascade mode selection. No other programming required.
Indicators: One green power LED. Four red LED indicators to monitor live inputs on channels 1-4. Two yellow LED indicators for inverted output and/or cascade output mode.
Input Channels: Four independent, isolated input channels CH1 to CH4

ModelInput Voltage
PDA1500-11585-130 VAC or VDC
PDA1500-230185-265 VAC or VDC

Inputs feature high common mode rejection, ideal for noisy environments.
Input Voltage Threshold: Input high voltage levels are different for AC and DC voltages. Instantaneous value is used to determine threshold for AC input - RMS equivalents are shown below.
PDA1500-115Input High Threshold Range:60 VAC RMS (85 VAC peak) or 85 VDC
Input Low Threshold Range:31 VAC RMS (44 VAC peak) or 44 VDC
PDA1500-230Input High Threshold Range: 131 VAC RMS (185 VAC peak) or 185 VDC
Input Low Threshold Range:66 VAC RMS (94 VAC peak) or 94 VDC
Input Current: 1.2 mA (typical) at "turn-on" or high input voltage
Propagation Delays: Input Propagation Delay to Logic Low: 4µs (typ); 15µs (max); Input Propagation Delay to Logic High: 8µs (typ); 40µs (max).
Input Impedance: PDA1500-115: >60kΩ total impedance per channel; PDA1500-230: >140kΩ total impedance per channel.
Input Overload: Must not exceed 50 mA DC (35 mA RMS) on input channels. Maximum input power dissipation is 230 mW. Surge protection included for up to 140 mA. Transient protection included for up to 500 mA.
Digital Outputs: Four TTL Logic (5V) independent digital outputs.
Output Logic Levels: Output Low: 0 to 0.33 V Output High: 4.4 to 5.0 V
Cascade Mode: Typically used in Boiler applications to monitor for and detect fault conditions.
Power: 12-24 VDC + 10%, 1.5 W max. Polarity sensitive. Short-circuit protected. Isolated.
Max Power Dissipation: PDA1500-115: 3W (total dissipation of unit) PDA1500-230: 4W (total dissipation of unit)
Isolation: 630 VRMS between input channels; 3750 VRMS input-to-power line; 3750 VRMS input-to-output; 1000 VRMS output-to-power line
Overvoltage: Maximum overvoltage (transient) allowable is 6000 V peak for 60 seconds.
Environmental: Operating temperature range: 0 to 65°C
Storage temperature range: 0 to 65°C
Relative humidity: 0 to 90% non-condensing
Connections: Fixed screw terminal blocks accept 12 to 30 AWG solid or stranded wire.
Enclosure: DIN rail-mountable ABS plastic enclosure. Color: black
DIN Rail Specification: 35mm "top hat" DIN rail required
Tightening Torque: Screw terminal connectors: 4.3 lb-in (0.56 Nm)
Overall Dimensions: Inch (mm) 3.00" x 3.63" x 2.38" (76.3 mm x 92.3 mm x 60.5 mm)(W x H x D)
Weight: 12 oz (340.2 g)
Warranty: 3 years parts & labor

OPERATION

The PDA1500 High Voltage AC/DC to Logic Level Converter accepts up to four high voltage input signals and outputs a TTL logic (5 V) signal representative of each input's status, whether high voltage is present or not.
Normal Mode
In Normal Mode operation, the converter detects the presence of high voltage on input channels CH1 to CH4. If high voltage is present, the corresponding output 1-4 will be high, as seen in Figure 4. If voltage is below the detection range, the corresponding output will be low.
Normal Mode for AC Limiter Switches

PDA1500_Normal_Mode_Fig4-1

Figure 4: Normal Mode Example

Normal Mode may be used to set alarm conditions on a Vigilante II annunciator when high voltage is not present on an input channel, such as when an interlock relay has opened. In this example, since limit switch 3 (relay 3) is open, high voltage is not present at input channel 3 (CH3). The resulting low output from output 3 triggers the Vigilante II annunciator to alarm the corresponding input, as well as sound the 85dB alarm in order to alert the operator of the alarm condition. This setup can be used to alarm based on safety interlocks, fuse failures, or any other condition that would break the high voltage line. In this mode, the converter's output condition matches the input condition.



Inverted Mode
In Inverted Mode operation, the state of all outputs is the inverse of what they would be in Normal Mode. The converter detects the presence of high voltage on input channels CH1 to CH4. If high voltage is present on an input channel, the corresponding output 1 to 4 will be low, as seen in Figure 5. If voltage is below the detection range on an input channel, the corresponding output will be high.

Inverted Mode for Pumps

PDA1500_Inverted_Mode_fig5-1

Figure 5: Inverted Mode Example

Inverted Mode may be used to set alarm conditions on a Vigilante II annunciator when high voltage is present on an input channel, such as when a relay closure supplied power to a pump. In this example, relay 2 has closed, applying power to pump 2. Input channel 2 (CH2) will detect high voltage. Because the converter is in Inverted Mode, the output is in the "Low" state, the opposite state of the input. Output channel 2 is subsequently Low. The Vigilante II is configured to light an LED on an input Low signal, and therefore the annunciator shows that pump 2 is active. The Vigilante II is configured to sound an 85 dB audible alarm while the alarm condition is present, and automatically clear when the alarm condition clears. In this mode, the converter's output condition is the opposite of the input condition.



Cascade Mode
Cascade Mode is a special operation mode used for the monitoring of high voltage interlocks where one failure causes a failure of all monitoring points further down in the system. Examples of this include the many interlocks on boiler systems, where a single failure can cause a cascade of failures later in the system. Cascade Mode will indicate the single point of failure in these series systems, as seen in Figure 6.

Cascade mode provides a digital output alarm state if the corresponding input channel is active, but the next subsequent input channel is inactive. This can be used to identify the single point of system failure, without indicating every alarm state throughout the linked series interlock system. Cascade mode utilizes exclusive NOR (inverting OR) logic.

Cascade Mode for Boiler System Control

PDA1500_Cascade_Mode_Fig6-1

Figure 6: Cascade Mode Example

Cascade Mode may be used to set alarm conditions for multiple relays or interlocks wired together in a series. In this configuration, the first interlock in a system to encounter a problem opens the high voltage circuit, and is the only alarm output triggered by the PDA1500. In this example, since the signal output for Interlock 2 is now cut, the interlock triggers the Vigilante II annunciator to turn off the entire system, and sound the 85dB alarm in order to alert the operator of the alarm condition. The LED indicating the point of failure on the Vigilante II Annunciator can remain lit until reset. In this case, the point of failure is pump-related at Interlock 2, so investigation into the problem can begin there. The corresponding LED on the PDA1500 is independent of the Vigilante II; LEDs on the PDA1500 (Live Inputs) are always ON when high voltage is present and always OFF when high voltage is not present. Notice how PDA1500 #1's output (O) is wired to PDA1500 #2's input (I) and vice versa. This allows the two PDA1500 units to properly monitor the inputs for Cascade Mode.

Inverted Cascade Mode
Inverted Mode may be applied to Cascade Mode. When the H/L pushbutton is latched in the recessed position, Inverted Mode is active. The outputs behave using the same logic as in Cascade Mode, but the output states are all inverted. This makes the Cascade Mode output function using exclusive OR (XOR) logic. Inverted Cascade Mode will also work across multiple units.

Multiple Unit Cascade Mode
Cascade Mode logic may be combined across multiple Logic Level Converters to monitor more than 3 alarm outputs (or 4 inputs). When wired together, output four (4) of a Logic Level Converter will monitor input CH4 and CH1 of the next Logic Level Converter wired in series with it. Multiple unit Cascade Mode may be used across an unlimited number of units. See Figure 6.

DIMENSIONS

PDA1500_Dimensions

Figure 7: Dimension Drawings

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