Panel to ESM(r) Interfacing

Overview

The Waukesha ESM (r) is an engine control unit made by Waukesha for their VHP series engines. When a unit with an ESM is connected to an EMIT panel, the panel will use a few signals to control the start, stop, and speed of the engine. Many concepts are similar to connecting to other engines.

Initial Setup

Navigate to Settings - Brain - Outputs Setup - ECU Selection, and select "Waukesha ESM".

Wiring

Wire table summary

Function	Direction	ESM Wire No.	ESM Wire Name	ESM Wire Color
Emergency Shutdown	Panel to ESM	1606	ESD	Yellow
Remote Speed Input	Jumper	1608	GOVREMSEL	Yellow
ESM Normal Start	Panel to ESM	1609	START	Yellow
ESM Normal Run	Panel to ESM	1611	RUN/START	Yellow
Panel Shutdown from ESM	ESM to Panel	1607	ENG ESD	White
4-20 mA Enable Jumper A	Jumper	1618	GOV 40	Tan
4-20 mA Enable Jumper B	Jumper	1619	GOV 41	Tan
4-20 mA Target Speed Signal	Panel to ESM	1614	GOVREMSP+	Light Green
4-20 mA Target Speed Return	Panel to ESM	1613	GOVREMSP-	Light Blue
Logic Ground	Panel to ESM	1111	LOGIC GND	Black
RS485-	Panel to ESM	1305	RS485-	Grey
RS485+	Panel to ESM	1306	RS485+	Grey
RS485 Shield	Panel to ESM	1145	RS485 SHD	Silver

Panel to ESM Connections

There are three discrete connections from the panel to the ESM: Run permissive, start initiate, and emergency stop. There is also one analog connection for target speed. The schematic should show a page where these land in that specific panel. The details of each signal is noted below.

ESM Normal Run

The ESM normal run wire is numbered 1611 from the engine. This wire needs 24VDC maintained to run. In the EMIT panel this will be powered from a relay that will be ON during run. Usually this relay coil is powered from the fuel valve output of the brain (Pin 10) or a digital output that is set to Fuel valve or Driven equipment ready. This relay will come on during the start sequence and turn off when the unit should shut down.

ESM Normal Start

The ESM normal start wire is numbered 1609 from the engine. This wire is pulsed with 24VDC for a second or two to start the engine. On the EMIT panel it will always be controlled from relay CR2 from output DO-2. This relay / output will turn on for a couple seconds during the start sequence when the start initiate should begein.

ESM Emergency Shutdown

The ESM emergency stop wire is numbered 1606. This wire needs 24VDC maintained to run. In the EMIT panel this will be routed through the cabinet E-stop switch and back to power, so that if the switch is pushed in the power is removed from the ESD wire.

ESM Speed Target Signal

The ESM speed target is a pair of wires that are numbered 1614 for signal and 1613 for return. These are an analog input on the ESM for the speed target. On the EMIT panel analog out 1 of the brain is always used for the speed target, which wires to this pair. AO-1 will go to the signal wire and the ground return will go to normal panel ground. In speed control setup the 4-20 mA range will match the idle to rated speed of the engine.

ESM to Panel Connections

Panel shutdown

The panel shutdown from ESM is on wire 1607 from the engine. This wire is powered to 24V while the unit is faulted. This should toggle a relay which has an output running to Brain DI-27 that is labeled "ESM RUN STATUS".

Jumpers

There are two jumpers needed:

• ESM GOVREMSEL wire 1608 needs to be wired to +24VDC to enable the remote speed input. This can be done somewhere in the EMIT panel or by the engine.
• GOV 40 - GOV 41 : These two wires (1618, 1619) should be tied together

ESM Data Connection

Connection

The ESM 485+/- wires shown in the wire table in an above section are inputs to a modbus slave port on the ESM. These will be wired back to pins 25,26 on the back of the DCT. In most cases there will be wires ran from the DCT to a relevant terminal block and shown on the schematic so the ESM 485 wires can land at the terminal block.

Setup

The EDT (engine data translator) in the DCT will be set up to communicate with the ESM and pull data back to the DCT. The EDT setup is found under Settings -> Engine Data Translator.

On the mode, set to "Wauk. ESM" for the original ESM or "Wauk. ESM2" for the newer ESM2. In either case, a lower section will show up where the target ID, baud rate, and line control mode will be shown. These settings will vary by engine and sometimes are configurable, but the setting on the EDT page needs to match the engine setting.

When working, the EDT tab on the home page will show some relevant engine data.

Start Sequence

• On power up, unit is STOPPED
  • START is off
  • RUN/START is off
• Operator presses RESET
  • Unit will go to STANDBY
• Operator presses START
  • Assuming all A and ESD faults are clear, unit goes to next state
• Blowdown, purge, prelube sequences will run if needed
• ESM Start Sequence
  • Run Relay energizes providing +24V to "ESM Normal Run/ Stop"
  • Annunciator provides momentary +24 pulse on "ESM Start Engine"
  • Panel goes to WAITING FOR ESM RUN
  • ESM will pre-lube and start the engine
  • Once rpm reaches 650, the next state is entered
  • If ESM fails to start engine in “ESM Max Startup Wait Time” setting time period, the system faults to stop state with fault code "ECU Failed to Start"
• Warmup
  • B1 and B2 counters begin counting down
  • The panel will hold idle until the idle hold condition is met (regardless of panel SPEED MODE switch position).
  • The analog out ‘SPEED TARGET’ will be at minimum
  • Panel will display “RUN” and “Idle permissive not met”
  • B1 and B2 timers will count down and expire normally. Operator RESET presses will reset these timers
• Running
  • Once the ‘Idle Hold Condition’ is met, speed control enters normal operation
  • The speed output to the ESM will now changed based on the operator SPEED MODE switch position
    • IDLE- remain at idle
    • MANUAL- Increase/Decrease speed with EMIT manual knob
    • AUTO- run to configured AUTO speed settings (e.g. fixed speed or controlling to suction pressure)