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