LMI Roytronic Series A Pump Externally Triggering or Pacing

Methods of Externally Triggering or Pacing A3, A7, and A8 Pumps

Method of Triggering A3, and A7 Pumps Through External Control Connector

Series A Pump Manual
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Switch or transistors must be capable of switching 24V DC at 15 milliamperes. Minimum time in low impedance state (ON) is 25 milliseconds. Minimum time in high impedance state (OFF) is 50 milliseconds.

NOTE: Pins 1 (Brown wire) and 2 (White wire) must be connected/ shorted together in order for the pump to be ‘ON’ in external mode.





Series A InstructionsThese pumps have two operating modes: Local (Pulse Indicator Light flashes green) and Remote (Pulse Indicator Light flashes yellow). Pressing the Power/ Mode Selection Button switches between Local and Remote modes. The default configuration for operating mode is Local mode.

When the pump is in Local mode the Remote On/Off input is ignored. When the pump is in Remote mode the Remote On/Off input is always monitored. The pump will return to the last power mode if power is interrupted.

Remote Mode Liquitron
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Control Modes

Local Mode

  • When in Local mode the A3 pump runs continuously at maximum speed.
  • When in Local mode A7 and A8 pumps run at the speed indicated by the speed knob.

Remote Mode (for A3, and A7)

Water Cooling TowerPins 1 (brown wire) and 2 (white wire) must be connected/shorted together in order for the pump to respond to pulses in external mode.

  • In Remote mode pulses occurring faster than a rate of 1200 pulses per minute (less than 50ms apart) and pulses with a duration of less than 25ms are ignored.
  • Pulses occurring between 240 strokes per minute (SPM) and 1200 pulses per minute results in the pump running at 240 SPM.
  • Pulses occurring at less than 240 SPM results in the pump stroking at that rate.

Remote Mode (for A8)

Pins 1 (brown wire) and 2 (white wire) must be connected/shorted together in order for the pump to respond to a milliamp signal.

In Remote mode the pump speed is controlled by a milliamp (mA) Analog Input signal. The factory default settings for the Analog Input are: 20mA input = maximum speed, 4 mA = 0 strokes per minute.

In the default settings, the fast level mA input is greater than the slow level mA input. This is known as direct action. In direct action when the mA input is at or above the setting for the fast level, the pump will run at maximum speed. When the mA input is below the setting for the slow level, the pump will stop.

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