Thomson MEC 20 V1.82 Manual

MEC 20

MICROPROCESSOR

ENGINE/GENERATOR CONTROLLER

(WITH REMOTE COMMUNICATION, EXPANSION OUTPUT MODULE &

EAP 110 REMOTE ANNUNCIATOR OPTIONS)

INSTALLATION, OPERATING &

SERVICE MANUAL

Software Version 1.82

PM047 Rev 13 05/03/30

9087A – 198th Street, Langley, BC Canada V1M 3B1 Telephone [phone] Telefax [phone] E-Mail: [e-mail] www.thomsontechnology.com

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

CONTENTS

1.	INTRODUCTION		1
	1.1.	PRODUCT REVISION HISTORY	1
	1.2.	GENERAL DESCRIPTION	3
2.	INSTALLATION		5
	2.1.	GENERAL INFORMATION	5
	2.2.	BATTERY SUPPLY INPUT	5
	2.3.	SPEED SENSING INPUT	6
	2.4.	DC VOLTAGE INPUTS	6
	2.5.	AC VOLTAGE INPUT	7
	2.6.	AC CURRENT INPUT	8
	2.7.	OUTPUTS	8
	2.8.	EXTERNAL PANEL CONTROL WIRING	8
	2.9.	REMOTE START CONTACT FIELD WIRING	9
	2.10.	REMOTE COMMUNICATION WIRING	9
	2.11.	EXPANSION OUTPUT MODULE LOCATION/INSTALLATION	10
	2.12.	MEC MOUNTING LOCATION/INSTALLATION	11
	2.13.	FACEPLATE MOUNTING DIMENSIONS	11
	2.14.	MEC 20 ASSEMBLY - SIDE VIEW	13
	2.15.	DIELECTRIC TESTING	14
3.	DESCRIPTION		14

PM047 Rev 12 03/03/04

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

3.1.		LEXAN FACEPLATE	14
3.2.		PRINTED CIRCUIT BOARD	17
4.	FAULT CIRCUIT DESCRIPTIONS		19
4.1.		MEC 20 FUNCTIONAL BLOCK DIAGRAM	20
4.2.		INTERNAL FAULT CIRCUITS	21
4.3.		DIGITAL FAULT INPUT CIRCUITS	22
4.4.		ANALOG FAULT INPUT CIRCUITS	23
5.	CONTROL OUTPUT CONTACT DESCRIPTIONS		28
5.1.		RUN, CRANK, COMMON FAIL OUTPUT CONTACTS	29
5.2.		PROGRAMMABLE OUTPUT CONTACTS	29
6.	REMOTE COMMUNICATION OPTION		34
7.	EXPANSION OUTPUT MODULE OPTION		37
8.	EAP 110 REMOTE ANNUNCIATOR OPTION		40
9.	OPERATING INSTRUCTIONS		41
9.1.		MEC 20 POWER-UP OPERATION SEQUENCE	41
9.2.		MEC 20 DISPLAY MENUS	41
9.3.		SEQUENCE OF OPERATION	48
9.4.		CONTROL PUSH-BUTTONS	55
10.	PROGRAMMING INSTRUCTIONS		57
10.1.		SECURITY PASSWORDS	57

PM047 Rev 12 03/03/04

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

10.2.	BASIC PROGRAMMING OPERATION	58
10.3.	MAIN PROGRAMMING MENU	59
10.4. ANALOG FAULT PROGRAMMING MENU		66
10.5. DIGITAL FAULT PROGRAMMING MENU		67
10.6.	CALIBRATION MENU	70

11.	PROGRAMMING SHEETS		80
11.1. SUMMARY CONFIGURATION DATA SHEET			80
11.2.		MAIN CONFIGURATION	81
11.3. ANALOG FAULT PROGRAMMING MENU			84
11.4. DIGITAL FAULT PROGRAMMING MENU			85
11.5.		CALIBRATION MENU	86
12.	SPECIFICATIONS		87
13.	CONNECTION DIAGRAM		88
14.	TROUBLE SHOOTING		89
15.	NOTES		92

PM047 Rev 12 03/03/04

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

1.INTRODUCTION

1.1.PRODUCT REVISION HISTORY

The following information provides an historical summary of changes made to this product since the original release.

1.1.1. Software Version

1.82 05/03/30	Revised Idle Control Logic for Digital Inputs #1,2
	Increased High Temperature Analog Shutdown High Limit
1.81 03/03/04	Changed Oil Pressure Sender Manufacturer requiring revised
	pressure/resistance calibration data
	New Oil Pressure Sender Thomson p/n-003654, Manufacturer-
	Datcon, p/n 102227.
	Discontinued Oil Pressure Sender Thomson p/n-000772,
	ManufacturerIsspro, p/n R9279C
	Note: The oil pressure senders are not interchangeable with the
	software versions.
1.8 02/09/09	Added Programmable Output Feature “EPS Supplying Load”
	Added Digital Input Feature “No-Load Test”
	Added New Digital Fault Names
	Basin Rupture
	ATS in Bypass
	Fuel Leak
	Vent Damper Fail
	High Fuel Level
	Low Fuel Press
	Bat Charger Fail
	Fail to Sync
	HighIntkManfTemp
	Added Independent Programming features for AMF Outputs
	Added references for EAP 110 Remote Annunciator
	Misc. Display & Menu changes

PM047 Rev 13 05/03/30

1

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

1.7 02/02/15	Key changes implemented as follows:
	• Auto Mains Failure (AMF) logic with new timers, control outputs
	and display features
	• Line to Neutral AC Voltage Display on 3 Phase 4 Wire Systems
	(neutral connection required)
	• Analog Shutdown Capability from Oil Pressure and
	Temperature Senders
	• Expanded oil pressure operation up to 150 PSI (was 100 PSI)
	• Single Point Calibration for Oil Pressure/engine temperature
	sender inputs (simplified calibration, field calibration is now
	mandatory)
	• Programmable Output features now expanded to map to every
	available fault circuit
	Add new Programmable Output features Engine Ready & Engine
	Run (Fuel)
	There were also minor changes that are reflected in the manual.
1.6 01/07/18	Added Ready to load programmable output and new Isspro Oil
	Pressure sender curves; increased standard digital & analog fault
	features.
1.5 00/09/20	Added kVA metering.
1.4 99/12/09	Added new digital faults labels and blank selections.
1.3 98/02/09	New version with communication features, expansion relay module
	capability, deletion of “horn” programming, deletion of cooldown
	shutdown programmability, deletion of “common fail”
	programmability and revised password number.
1.2 97/06/04	Original version.

1.1.2. Operating & Service Manual Version

Rev 13 05/03/30	Added descriptive information for new software version 1.82
Rev 12 03/03/04	Changed Oil pressure/resistance calibration data and new software
	version 1.81.

PM047 Rev 13 05/03/30

2

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

Rev 11 02/09/09	Added descriptive information for new software version 1.8
Rev 10 02/02/15	Added descriptive information for new software version 1.7
Rev 9 01/10/17	Clarification of faults required for C282 or NFPA 110.
Rev 8 01/07/18	Addition of “Static Precaution”; deletion of calibration jumpers to
	requiring external calibration resistors/potentiometers; standard
	fault circuits increase from 12 to 28; Ready status changes to
	“Ready to Load”; changes in temperature and pressure calibrations;
	extended temperature ratings.
Rev 7 00/12/01	Minor text changes.
Rev 6 00/10/06	Added KVA metering feature.
Rev 5 00/04/06	Changes made to digital fault labels.
Rev 4 99/02/01	Remote communication wiring changes; multiple controllers that
	can be connected changes from 5 to 10.
Rev 3 98/05/08	Corrected minor errors.
Rev 2 98/02/18	New version with communication features; expansion relay module
	capability and revised password number.
Rev 1 98/01/22	Corrected minor errors.
Rev 0 97/06/04	Original release.

Contact Thomson Technology, to obtain applicable instruction manuals. Soft copy of most current version is available at www.thomsontechnology.com.

1.2.GENERAL DESCRIPTION

The Thomson Technology MEC 20 Microprocessor-based Engine/Generator Controller utilizes the latest advancements in microprocessor design technology for the control and monitoring of engine-generator sets. The MEC 20 provides a comprehensive array of operational, protection and display features for automatically controlling an engine/generator set. All standard and optional features of the MEC 20 are configurable from the front panel LCD display and are security password protected. The LCD display screen prompts are in plain English, providing a user-friendly operator interface with many display options available. The microprocessor design provides high accuracy for

PM047 Rev 13 05/03/30

3

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

all voltage monitoring, current monitoring and timing functions as well as providing many standard features which were previously only available as expensive add-on optional features.

The MEC 20 provides the following advanced features:

•Up to 28 alarm/shutdown fault circuits utilizing analog and digital inputs.

•Standard model meets or exceeds CSA C282, NFPA 110 Level 1 generator set control requirements.

•RS 422 remote communication port.

•Expansion output module communication port for individual output fault contact capability.

•Backlit LCD display screen with alpha-numeric readout for display and programming.

•Digital 3-phase voltage, 3-phase current, KVA and frequency metering for generator output.

•Non-volatile memory retains logic and set points if control power is lost.

•Direct 3-phase voltage sensing inputs on generator supply from 120Vac up to 600Vac (nominal).

•Security password-protected programming levels.

•Self diagnostic features continuously verify processing, I/O and memory circuits.

•Superior EMI/RFI noise immunity and surge performance features as per IEEE C62.41 requirements.

•Dual microprocessor design provides independent speed sensing circuitry for higher performance.

CAUTION

contents subject to damage by

STATIC ELECTRICITY

This equipment contains static-sensitive parts. Please observe the following anti-static precautions at all times when handling this equipment. Failure to observe these precautions may cause equipment failure and/or damage.

PM047 Rev 13 05/03/30

4

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

•Discharge body static charge before handling the equipment (contact a grounded surface and maintain contact while handling the equipment, a grounded wrist strap can/should also be utilized).

•Do not touch any components on the printed circuit board with your hands or any other conductive equipment.

•Do not place the equipment on or near materials such as Styrofoam, plastic and vinyl. Place the equipment on grounded surfaces and only use an anti-static bag for transporting the equipment.

2.INSTALLATION

2.1.GENERAL INFORMATION

NOTE:

Installations should be done according to all applicable electrical regulation codes as required.

The following installation guidelines are provided for general information only pertaining to typical site installations. For specific site installation information, consult Thomson Technology as required. Note: Factory installations of THOMSON TECHNOLOGY supplied control panels that have been tested and proven may deviate from these recommendations.

CAUTION!!!

All installation and/or service work performed must be done by qualified personnel only. Failure to do so may cause personal injury or death.

2.2.BATTERY SUPPLY INPUT

The MEC 20 can operate on any battery supply from 10 to 30 volts DC. The battery DC negative or common conductor must be grounded to the main generator-set frame ground. The MEC 20 is internally protected by a solid state type fuse that protects it from inadvertent shorts on the output terminals. The solid state fuse will automatically reset when the overcurrent condition is removed. Wiring from the engine cranking

PM047 Rev 13 05/03/30

5

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

battery to the control panel should conform to the following guidelines to avoid possible controller malfunction and/or damage.

2.2.1. Avoid wiring from the engine starter terminals - wiring should go directly from the battery terminals to the engine control panel (to avoid voltage drop in the starter cables and starter motor commutator noise). Note: Unit mounted control panels with short wiring runs may utilize connections from the starter terminals provided that the specific application is tested satisfactorily.

CAUTION!!!

The battery charger must be turned off before battery cables are removed from the battery (i.e. for servicing). Failure to do so may subject the control panel to an overvoltage condition in which damage may result.

2.2.2.Wiring from battery to engine control panel should be two - #14 AWG (2.5mm2) wires (i.e. do not use the engine block as one of the common conductors).

2.2.3.Under noisy environments (i.e. gas engines with high voltage ignitions, etc.), wiring from battery should be a twisted pair of #14 AWG (2.5mm2) wires.

2.3.SPEED SENSING INPUT

Field wiring of the speed sensing signal wires should conform to the following guidelines to avoid possible controller malfunction and/or damage:

2.3.1.Wiring from magnetic pickup must utilize a 2 conductor shielded/twisted cable. The drain (shield) wire must be connected at the control panel end only.

2.3.2.Magnetic pickup voltage at cranking speed must be greater than 3.0VAC. At nominal speed, magnetic pickup voltage should be between 3.0 and 5VAC.

2.3.3.A single dedicated magnetic pickup is recommended for connection to the speed sensing input terminals. Note: One common magnetic pickup may be utilized for the system provided specific test measurements are done with the equipment installed (i.e. mag pickup voltage levels meet the required levels).

2.4.DC VOLTAGE INPUTS

All DC voltage inputs to the MEC 20 are optically isolated and filtered for protection from noise spikes and transients Input wiring must be routed so that it is not near electrically "noisy" wiring such as ignition, starter wires or main AC power conductors. All contacts

PM047 Rev 13 05/03/30

6

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

must be “dry” (i.e. non-powered) and one side must be connected to the common DC negative conductor.

2.5.AC VOLTAGE INPUT

The MEC 20 can accept direct AC voltage input from 120-600Vac (nominal). Note: Direct input voltage sensing can only be used when the generator utilizes a single phase 3 wire or 3 phase, 4 wire distribution system with a solidly grounded neutral conductor. For 3 phase 3 wire systems (i.e. no neutral) or high voltage systems, potential transformers must be used. Refer to FIGURES #1 - 4 for voltage sensing connections. To display generator line to neutral voltage in a 3 phase 4 wire system, the neutral must be connected as shown.

MEC 20

A B C N

VA

VB

VC

VN

GRD

GRD

VOLTAGE INPUTS

600VAC L-L, 347VAC L-N 380VAC L-L, 220VAC L-N 480VAC L-L, 277VAC L-N 208VAC L-L, 120VAC L-N

A B C

N

GEN. GRD

	MEC 20	L1	L2	N
	VA
	VB
	VC
	No Connection
	VN
	GRD
	GRD
	VOLTAGE INPUTS		L2
	240VAC L-L, 120VAC L-N	L1
	Note: L1 and L2 phase
	voltages must be 120Vac			N
	when referenced to common	GEN.
				GRD
	neutral. (Delta connected

generators required PTs as per figure#3 & no phase C PT)

FIGURE #1

3Ø, 4W 208/380/480/600VAC DIRECT SENSING SOLIDLY GROUNDED NEUTRAL SYSTEM

MEC 20		A	B	C	N
VA
	120
VB
	120
VC
VN	120
GRD	GRD
	GRD
SECONDARY PT VOLTAGE			B
208VAC L-L, 120VAC L-N		A		C
120VAC L-L, 69VAC L-N
			GEN.	N

FIGURE #3

3Ø, 4W WYE PT's

FIGURE #2

1Ø, 3W 120/240VAC DIRECT SENSING SOLIDLY GROUNDED NEUTRAL SYSTEM

	MEC 20	A	B	C
	VA
	VB	120
	VC GRD	120
	VN
	No Connection
	GRD
		GRD
	SECONDARY PT VOLTAGE		B
	120VAC L-L	A		C

(NO NEUTRAL)

N

GEN.

FIGURE #4

3Ø, 3W DELTA PT's

G:\ENGINEER\PRODUCTS\MEC20\MEC20_08.VSD REV. 2 02/02/22

PM047 Rev 13 05/03/30

7

Thomson Technology

#14 AWG (2.5mm2)

#16 AWG (1.5mm2)

#14 AWG (2.5mm2)

#14 AWG (2.5mm2) (To pilot relays)

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

2.6.AC CURRENT INPUT

Current transformers (CT’s) must be used to supply the MEC 20 current inputs. CT polarity is not critical for correct circuit operation. Note: The CT secondary common conductors must be externally grounded for correct operation. CT’s must be rated for a minimum of 1.5VA output at the specified accuracy.

CAUTION!!!

When installing or performing any service work on CT circuits, always de-energize the system before proceeding with any work. Never open circuit an energized CT as extreme high voltages may result which may cause serious injury or death.

2.7.OUTPUTS

All outputs from the MEC 20 are relay driven contacts. Relay contacts have a 10A/240Vac resistive, 8A/24Vdc (3 Amp inductive 0.4pf), rating and are isolated Form A & Form C types. Interposing relays are recommended between the MEC 20 outputs and end devices to prevent internal damage due to possible excessive current draw and/or damage should an external fault occur. Note: These outputs will require external overcurrent protection (Maximum 10 Amp).

The use of AC or DC operated solenoids or relays in control systems can sometimes cause high voltage spikes on the DC power supply, which may cause electronic devices to fail. Transient suppression devices are recommended for all inductive devices sharing wiring or if physically located near engine/generator control panels. For DC operated relays or solenoids, use a suitably rated counter EMF Diode (or commonly known as “freewheeling” diode). For AC operated relays or solenoids, use a suitably rated metal oxide varistor (MOV) or capacitor/resistor suppressor.

2.8.EXTERNAL PANEL CONTROL WIRING

As a minimum, all control wiring shall conform to the local regulatory authority on electrical installations. Specific wire sizes for typical circuits (of distances up to 100ft (30m) ) are as follows:

2.8.1. Battery Control Power

2.8.2. Engine Alarm/Shutdown Contacts

2.8.3. Remote Start Contact for Transfer Switch 2.8.4. Crank & Preheat Output Wiring

PM047 Rev 13 05/03/30

8

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

2.8.5. Speed Sensing Wiring		#16 AWG (1.5mm2) 2
		Conductor Shielded Cable
2.8.6.	Metering Voltage Inputs	#16 AWG (1.5mm2)
2.8.7.	Metering Current Inputs (from CT’s)	#14 AWG (2.5mm2)

For distances exceeding 100 Ft. (30m) consult THOMSON TECHNOLOGY.

For unit mounted control panels, wire sizes may be reduced to the next smallest wire size available.

2.9.REMOTE START CONTACT FIELD WIRING

Field wiring of a remote start contact from a transfer switch to a control panel should conform to the following guidelines to avoid possible controller malfunction and/or damage.

2.9.1.Remote start contact wires (2 - #14 AWG (2.5mm2) should be run in a separate conduit.

2.9.2.Avoid wiring near AC power cables to prevent pick-up of induced voltages.

2.9.3.An interposing relay may be required if field wiring distance is excessively long (i.e. greater than 100 feet (30m) and/or if a remote contact has a resistance of greater than 5.0 ohms.

2.9.4.The remote start contact must be voltage free (i.e. dry contact). The use of a “powered” contact will damage the engine controller.

2.10.REMOTE COMMUNICATION WIRING

All interconnecting wiring to/from the MEC 20 engine/generator controller communication port shall utilize #22 AWG (min.) 8 conductor, twisted, shielded cable with RJ45 connectors. The drain (shield) wire must be connected at the MEC 20 controller end only. Refer to Section 6 for further information.

Communication cable from the controllers’ com port must be suitably routed to protect it from sources of electrical interference. Guidelines for protection against possible electrical interference are as follows:

•Use high quality, 8 conductor shielded cable only with drain wire grounded at the controller end only.

•Route the communication cable at least 3M (10”) away from sources of electrical noise such as variable speed motor drives, high voltage power conductors, UPS systems, transformers, rectifiers etc.

PM047 Rev 13 05/03/30

9

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

•Use separate, dedicated conduit runs for all communication cables. Do not tightly bundle communication cables together in the conduit. Conduit should be ferromagnetic type near sources of possible electrical interference. The entire length of conduit should be grounded to building earth ground.

•When communication cables must cross over low or high voltage AC power

conductors, the communication cables must cross at right angles and not in parallel with the conductors.

For additional information on protection against electrical interference, contact Thomson Technology factory.

2.11. EXPANSION OUTPUT MODULE LOCATION/INSTALLATION

The expansion module(s) are to be mounted inside a control panel using four screws with stand-offs provided. The expansion module must be mounted within 300 metres (1000 feet) wiring distance from the MEC 20 using an 8 conductor shielded cable provided with the module. The communication cable must not be bundled together with other control wiring inside the panel. Mounting dimensions for the expansion output module are shown in FIGURE #5.

0.00 mm

152.4 mm

7.62 mm

152.4 mm		137.16mm

4 HOLES

4.75 MM DIAMETER (3/16" DRILL)

	7.62 mm							0.00 mm
137.16 mm

FIGURE #5: MEC 20 EXPANSION MODULE MOUNTING DIMENSIONS

G:\ENGINEER\PRODUCTS\MEC20\MEC20_14.VSD

DRAWING SCALE .75:1

PM047 Rev 13 05/03/30

10

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

2.12. MEC MOUNTING LOCATION/INSTALLATION

The MEC 20 Engine-generator controller is designed for mounting directly onto a control panel door. Considerations should be given for the following:

•The controller should be installed in a dirt free, dry location away from extreme heat sources.

•The LCD window should be installed at an optimum height for operator viewing.

•Adequate space should be provided around the rear of the MEC 20 circuit board for control wiring.

•Verify that the intended AC voltage input to the controller does not exceed the maximum allowable level on the control panel door as per the applicable control panel certification standard.

The MEC 20 controller can be installed onto a door of a control panel using one of the following methods:

•The first method requires a special door cutout for the LCD display and LED’s as shown in FIGURE #6. This mounting method requires the lexan faceplate to be mounted directly onto the door of the control panel. The controller must be disassembled to mount on the door, then re-assembled. Refer to FIGURE #7 for correct assembly location of all parts.

•The second method of controller mounting requires a factory supplied adapter faceplate as shown in FIGURE #8. This method only requires a single large rectangular hole to be cut out of the door as shown in FIGURE #9.

2.13. FACEPLATE MOUNTING DIMENSIONS

PM047 Rev 13 05/03/30

11

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

166 mm.

C

20 mm. 32 mm.

268 mm.

C TOP

126 mm. 126 mm.

9 HOLES

80 mm. 6 mm. DIAMETER

(1/4" DRILL)

CUTOUT

8 mm.				8 mm.

OUTLINE OF PRINTED CIRCUIT

BOARD UNDER PANEL DOOR

G:\ENGINEER\PRODUCTS\MEC20_07.VSD

24 mm. 24 mm.

49 mm. 49 mm.

FIGURE #6

PM047 Rev 13 05/03/30

12

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

2.14. MEC 20 ASSEMBLY - SIDE VIEW

FRONT	PANEL DOOR	REAR
	MEC 20 PCB
		MEC 20 REAR COVER
PEM STUD		#8-32 × 3/8" MACHINE SCREW
#8-32 × 1"
		# 8-32 INTERNAL TOOTH LOCK WASHER
1/2" NYLON SPACER		1.25" ALLUMINUM STANDOFF (HEX)
(#8-32 CLEARANCE
UNTHREADED)		#8-32 THREAD

HIGH VOLTAGE

MYLAR BARRIER #8-32 INTERNAL TOOTH LOCK WASHER (mounts on bottom

right hand corner, as viewed from rear)

G:\ENGINEER\PRODUCTS\MEC20_09.VSD Rev. 0 97/06/02

FIGURE #7

Notes:

1.Ensure that all lockwashers are installed as shown above.

2.The high voltage mylar barrier (P/N TMW;10805;1) must be installed as shown when the MEC 20 is installed onto the door of a control panel.

3.When the MEC 20 is installed on a door without 1” PEM studs, 1” machine screws must be used.

PM047 Rev 13 05/03/30

13

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

		11.5 in	TOP
		C
			9 HOLES
			1/4" DIAMETER
		CUTOUT
in	C
7.5
			4 STUDS #8/32
			1/4"
			1/4"
		FIGURE #8: ADAPTER FACEPLATE
		5.5 in
		C
3.5 in		10.875 in
	C	in
		6.875

FIGURE #9: DOOR CUTOUT FOR ADAPTER FACEPLATE

G:\ENGINEER\PRODUCTS\MEC20_11.VSD Rev. 1 00/07/13

2.15. DIELECTRIC TESTING

Do not perform any high voltage dielectric testing on the control panel with the MEC 20 connected in the circuit as serious damage will occur to the controller. All AC control fuses connected to the MEC 20 must be removed if high voltage dielectric testing is performed on the control panel.

3.DESCRIPTION

The MEC 20 controller consists of three parts; a Lexan faceplate, which is mounted externally on the enclosure door, a printed circuit board (PCB) which is mounted inside the enclosure door, and a rear cover for the PCB.

3.1.LEXAN FACEPLATE

The Lexan faceplate is shown as in FIGURE #10. The Lexan push-buttons are

PM047 Rev 13 05/03/30

14

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

connected to the main PCB via plug-in ribbon cable. The main features of the Lexan faceplate are described as follows with reference to FIGURE #10.

13	1							4
								11
3	MICROPROCESSOR ENGINE CONTROLLER							12
			MEC 20
14	ALARM						READY
								5
	SHUTDOWN						SPEED SIGNAL
2		SILENCE	LAMP TEST		RESET			8
	EXIT	DECREMENT		INCREMENT		ENTER
7								9
6								10
	RUN		OFF	AUTO		LOAD	EMERGENCY
						TEST	STOP
MEC20_03.VSD	Rev 2 01/07/09

FIGURE #10

LCD viewing window. The LCD display is mounted on the main PCB that is visible through the lexan faceplate viewing window.

EXIT push-button. The EXIT function is used to scroll backwards through the status menus or programming prompts to the previous item. The EXIT function is used to “exit” the programming menu by holding this button down for approximately 2 seconds while in the programming mode.

DECREMENT push-button. The DECREMENT function is used to change a programming value while in the programming mode. When this pushbutton is held down, the displayed value will be “decremented” to a lower value as desired. Note: The longer the push-button is held down, the faster the value will be decremented.

INCREMENT push-button. The INCREMENT function is used to change a programming value while in the programming mode or to select a desired programming menu loop. When this push-button is held down, the displayed value will be “incremented” to a higher value as desired. Note:

PM047 Rev 13 05/03/30

15

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

11

12

13

14

The longer the push-button is held down, the faster the value will be incremented.

ENTER push-button. The ENTER function is used to scroll forwards through the status menus or programming prompts to the next item. The ENTER function is used to “enter” a programming mode as well as accepting changed programming values. Note: In the programming mode, the longer the ENTER push-button is held down, the faster the next menu prompts will appear.

RUN push-button and LED light viewing window. The RUN function is used to initiate a manual start signal to the engine-generator set. Refer to the operating instructions for detailed information.

OFF push-button and LED light viewing window. The OFF function is used to initiate a stop signal to the engine-generator set. Refer to the operating instructions for detailed information.

AUTO push-button and LED light viewing window. The AUTO function is used to initiate automatic operation of the engine-generator set. Refer to the operating instructions for detailed information.

LOAD TEST push-button and LED light viewing window. The LOAD TEST function is used to initiate load test of the engine-generator set when connected to an associated transfer switch. Refer to the operating instructions for detailed information.

EMERGENCY STOP push-button and LED light viewing window. The EMERGENCY STOP function is used to initiate an emergency stop signal to the engine-generator set. Refer to the operating instructions for detailed information.

READY LED light viewing window. The READY LED illuminates when the engine-generator set is set for automatic operation and no shutdown or alarm faults have been activated.

SPEED SIGNAL LED light viewing window. The SPEED SIGNAL LED illuminates when the engines speed signal is detected (i.e. the engine is turning over).

ALARM LED light viewing window. The ALARM LED illuminates (flashes) when any pre-programmed alarm fault has been activated.

SHUTDOWN LED light viewing window. The SHUTDOWN LED illuminates (flashes) when any pre-programmed shutdown fault has been activated.

PM047 Rev 13 05/03/30

16

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

3.2.PRINTED CIRCUIT BOARD

The printed circuit board (PCB) is shown in FIGURE #11. The PCB contains the following user interface items:

MEC 20 CIRCUIT BOARD LAYOUT

B+ B- GRD TB4

TB2 MP1 MP2 1

17

J6

EXP	R115	TB1
RJ45	CONTRAST	IN
		IC
J7		IB
COM		IA
RJ45		VN
WATCHDOG		VC
REMOTE START		VB
CRANK
RUN		VA
COM FAIL
	TB3 18	38

G:\ENGINEER\PRODUCTS\MEC20_02.VSD Rev. 2 01/07/09

DRAWING SCALE (mm) = .6:1

FIGURE #11

PM047 Rev 13 05/03/30

17

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

3.2.1. TERMINAL BLOCKS

Four terminal blocks are located on the PCB as follows:

TB1 AC Voltage and Current sensing terminal block (120-600VAC & 0- 5AAC)

	WARNING!!!
	Voltage sensing circuits are capable of lethal voltages while
	energized. Current transformer (CT) secondary circuits are capable
	of generating lethal voltages when open circuited with their primary
	circuit energized. Standard safety procedures should be followed
	and be performed by qualified personnel only. Failure to do so may
	cause personal injury and/or death.
TB2	Speed sensing and digital contact input terminal block
TB3	Output contacts and engine temperature/pressure input signal terminal
	block
TB4	DC power input and ground connection terminal block

3.2.2. DIAGNOSTIC LED’S

The MEC 20 controller provides five diagnostics LED lights that are mounted on the rear of the printed circuit board as per FIGURE #11. Their functions are described as follows:

3.2.2.1.WATCHDOG

This LED flashes on and off at irregular intervals which indicates that the microprocessor is functioning normally.

3.2.2.2.REMOTE START

This LED is illuminated whenever the MEC 20 has received a remote start signal.

3.2.2.3.CRANK

This LED is illuminated whenever the MEC 20 is initiating an engine cranking signal.

PM047 Rev 13 05/03/30

18

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

3.2.2.4.RUN

This LED is illuminated whenever the MEC 20 has called the engine to run.

3.2.2.5.COMMON FAIL

This LED is illuminated whenever the MEC 20 has initiated a common fail signal (i.e. whenever an alarm or shutdown fault has been activated). Note: All LED’s will be illuminated whenever a lamp test function is

performed.

3.2.3. CONTRAST ADJUSTMENT (R115)

A contrast adjustment potentiometer is located on the rear of the PCB and is factory set for ambient temperatures of 15° to 30° Celsius. For different ambient temperatures, consult the factory for adjustment procedures.

3.2.4. COMMUNICATION PORTS

Two RJ45 communication ports are provided on the circuit board for optional features as follows:

3.2.4.1J6 - EXP This port is utilized to interconnect an external expansion module for additional output contacts and/or the EAP 110 remote annunciator. Refer to Section 7.0 & 8.0 for additional information.

3.2.4.2J7 - COM This port is utilized to interconnect to a remote communication system for remote monitoring and control. Refer to Section 6.0 for additional information.

4.FAULT CIRCUIT DESCRIPTIONS

The MEC 20 engine-generator controller utilizes many analog and digital inputs to perform both monitoring and control functions. Three types of fault circuits are used to monitor and control the engine-generator set. The first type is Internal Fault Circuits that are derived from a combination of digital and analog inputs. The second type is Digital Input Fault circuits that are initiated from external contact inputs. The third type is Analog Input Fault circuits that are initiated from external analog signal inputs. The following functional block diagram (FIGURE #12) shows how all input/output fault circuits are organized.

PM047 Rev 13 05/03/30

19

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

4.1.MEC 20 FUNCTIONAL BLOCK DIAGRAM

			FEATURE		FACTORY PROGRAMMED	CUSTOMER CONFIGURED	OUTPUT CONTACTS
					STANDARD FAULTS	FAULTS
MAGNETIC					OVERSPEED
PICKUP
					SHUTDOWN
			RPM	FAULT	LOSS OF SPEED
			DISPLAY	LOGIC	ALARM/SHUTDOWN
					OVERCRANK
					SHUTDOWN
			AUTO PUSHBUTTON		SWITCH NOT IN AUTO
				LOGIC
					ALARM
ENGINE TEMPERATURE					LOW ENGINE TEMP.
SENDER			TEMP.	FAULT	ALARM
					HIGH ENGINE TEMP.
			DISPLAY	LOGIC	ALARM
					HIGH ENGINE TEMP.
					SHUTDOWN
ENGINE OIL PRESSURE					LOW OIL PRESSURE
SENDER			PRESS.	FAULT
					ALARM
			DISPLAY	LOGIC	LOW OIL PRESSURE
					SHUTDOWN
					LOW BATTERY		2
–	+	BATTERY	DC		VOLTAGE ALARM
		VOLTAGE		FAULT	HIGH BATTERY
			VOLT	LOGIC	VOLTAGE ALARM
			DISPLAY
					WEAK BATTERY
					ALARM
	3 PHASE AC		AC	FAULT	UNDERVOLTAGE		2
	V	VOLTAGE	VOLT/		OVERVOLTAGE
			FREQ.	LOGIC	UNDERFREQUENCY
			DISPLAY		OVERFREQUENCY
	3 PHASE AC		AC
		CURRENT		FAULT	OVERCURRENT		2
			CURRENT	LOGIC
			DISPLAY
DIGITAL INPUT
CONTACTS (N/O or N/C)
	1				LOW OIL PRESSURE
					SHUTDOWN
	2				HIGH ENGINE TEMP.
					SHUTDOWN
							2
					LOW COOLANT
	3
					LEVEL SHUTDOWN
	4				LOW FUEL LEVEL
					ALARM
	5			FAULT		DIGITAL FAULT #5
	6			LOGIC		DIGITAL FAULT #6
	7			1		DIGITAL FAULT #7
	8					DIGITAL FAULT #8
	9					DIGITAL FAULT #9
	10					DIGITAL FAULT #10
	11					DIGITAL FAULT #11
	12					DIGITAL FAULT #12
			E. STOP
		N/O			EMERGENCY STOP

FIGURE #12

RUN

10A/240Vac, 8A/24Vdc RESISTIVE

CRANK

10A/240Vac, 8A/24Vdc RESISTIVE

COMMON FAIL CONTACT 10A/240Vac, 8A/24Vdc RESISTIVE

PROGRAMMABLE CONTACT #1 10A/240Vac, 8A/24Vdc RESISTIVE

PROGRAMMABLE CONTACT #2 10A/240Vac, 8A/24Vdc RESISTIVE

PROGRAMMABLE CONTACT #3 10A/240Vac, 8A/24Vdc RESISTIVE

PROGRAMMABLE CONTACT #4 10A/240Vac, 8A/24Vdc RESISTIVE

NOTES:

1DIGITAL FAULT LABEL LIST – EACH POINT PROGRAMMABLE

2PROGRAMMABLE FUNCTION LIST

G:\ENGINEER\PRODUCTS\ MEC20_10.VSD Rev. 3 02/02/20

PM047 Rev 13 05/03/30

20

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

4.2.INTERNAL FAULT CIRCUITS

The MEC 20 Engine Controller provides four internally activated fault circuits as described below. All internal fault circuits are provided as standard with every MEC 20 controller.

4.2.1. OVERCRANK

The overcrank fault circuit is initiated when the engine fails to start after the selected crank time or number of crank cycles. The overcrank fault circuit is internally programmed as a latching shutdown fault and is not user programmable. Refer to the programming instructions for further information.

4.2.2. OVERSPEED

The overspeed fault circuit is initiated when the engine’s speed has increased above the overspeed setpoint. The overspeed fault circuit is internally programmed as a latching shutdown fault. The overspeed shutdown fault circuit is programmable for the percentage of nominal engine speed (i.e. overspeed setpoint) and for the transient time delay period. The programming prompts for overspeed are located in the main menu programming loop. Refer to the programming instructions for further information.

4.2.3. LOSS OF SPEED

The loss of speed fault circuit is initiated when the engine’s speed sensing circuit does not detect a speed signal for a period more than 2 seconds following a run signal. The loss of speed fault circuit may be user programmed as a latching shutdown fault or alarm only. The programming prompts for loss of speed are located in the main menu programming loop. Refer to the programming instructions for further information.

4.2.4. SWITCH NOT IN AUTO

The “Switch Not In Auto” fault circuit is initiated when the controller’s operating mode switch is changed from the auto position to any other position via the front mounted keypad. This fault is internally programmed as a non-latching alarm. In the main programming loop, this alarm may be user programmed to initiate the common fail output relay.

PM047 Rev 13 05/03/30

21

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

4.3.DIGITAL FAULT INPUT CIRCUITS

The MEC 20 Engine Controller provides up twelve digital fault input circuits that are user programmable. Each digital fault input circuit is activated via a remote sensing contact that is external to the controller.

Each digital fault input circuit may be programmed with a unique fault label description as stored in the controller’s non-volatile memory. The following digital fault labels are provided in each MEC 20 engine controller:

AIR DAMPER TRIPPED	HIGH OIL TEMP
BAT CHARGER INPUT FAIL	HIGH WINDING TEMP
BAT CHRG TROUBLE	IDLE
BREAKER TRIPPED	LOW COOLANT LEVEL
DC FAIL	LOW ENGINE TEMP
FAILED TO SYNC	LOW FUEL PRESS
GEN BREAKER OPEN	LOW FUEL LEVEL
GROUND FAULT	LOW OIL LEVEL
HIGH BEARING TEMP	LOW OIL PRESSURE
HIGH COOLER VIBRATION	REMOTE EMERG. STOP
HIGH ENGINE TEMP	REVERSE POWER
HIGH ENGINE VIBRATION	BASIN RUPTURE
HIGH FUEL LEVEL	ATS IN BYPASS
HIGH OIL LEVEL	FUEL LEAK
NO LOAD TEST	LOW FUEL PRESS
*HIGHINTKMANFTEMP	BAT CHARGER FAIL
VENT DAMPER FAIL
HIGH FUEL LEVEL
FAIL TO SYNC
“Blank” (i.e. no text for unused inputs)

Note: Up to six custom ”user defined” fault label names may be specified for the MEC 20 controller at time of purchase. The six custom fault label names cannot be changed once shipped from the factory.

4.3.1. FACTORY PROGRAMMED DIGITAL FAULT CIRCUITS

The MEC 20 is supplied from the factory programmed with twelve standard digital fault circuits as follows:

PM047 Rev 13 05/03/30

22

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

FAULT	FAULT	INPUT
NAME	ACTION	TERMINAL #
Low Oil Pressure	Shutdown	1
High Engine Temperature	Shutdown	2
Battery Charger Input Fail	Alarm	3
Low Fuel Level	Alarm	4
Digital Input #5	Alarm	5
Digital Input #6	Alarm	6
Digital Input #7	Alarm	7
Digital Input #8	Alarm	8
Digital Input #9	Alarm	9
Digital Input #10	Alarm	10
Remote Emergency Stop	Shutdown	11
Idle	N/A	12

Refer to Section 11.4 Digital Fault Programming Menu for the factory default settings.

Note: Fault Input #5 - #10 must be customer configured unless specified at time of order.

All faults require a customer connected contact to the MEC 20 input terminal as indicated. All fault circuits may be user field programmed for different control functions or alternate fault names.

Note: For CSA C282 applications the controller will be factory supplied with Low coolant level shutdown in place of Battery charger input fail alarm. Refer to the programming instructions for further information on digital fault circuits.

Note: Shutdown functions for Low Oil Pressure and High Engine Temperature may alternatively be provided via analog pressure and temperature sender inputs if programmed accordingly in the analog fault programming menu. Refer to Section 11.3 for further information.

4.4.ANALOG FAULT INPUT CIRCUITS

The MEC 20 Engine Controller provides up to fifteen analog fault input circuits that are user programmable. The controller is supplied from the factory with fifteen standard

PM047 Rev 13 05/03/30

23

Thomson Technology

MEC 20 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER

analog fault circuits. Each analog fault input circuit is activated via specific analog signal type. Refer to Section 11.3 Analog Fault Programming Menu for the factory default program settings for each analog fault provided.

WARNING!!!

The analog protection circuits for voltage, frequency, current, engine oil pressure, engine temperature and engine speed will be set at factory default settings only. Final settings will be required to be set by the commissioning authority. Failure to do so may result in severe equipment failure or damage.

4.4.1. ANALOG FAULT CIRCUITS

The MEC 20 is supplied from the factory with fifteen standard analog fault circuits as follows:

FAULT	FAULT	INPUT
NAME	ACTION	SIGNAL
Undervoltage	Shutdown	Generator voltage
Overvoltage	Shutdown	Generator voltage
Underfrequency	Alarm	Generator frequency
Overfrequency	Alarm	Generator frequency
Overcurrent	Alarm	Generator current
Weak battery	Alarm	Battery voltage
Low battery voltage	Alarm	Battery voltage
High battery voltage	Alarm	Battery voltage
Low engine temperature	Alarm	Engine temperature
High engine temperature #1	Alarm	Engine temperature
High engine temperature #2	Shutdown	Engine temperature
Low oil pressure #1	Alarm	Oil pressure
Low oil pressure #2	Shutdown	Oil pressure
Overspeed	Shutdown	Engine speed
Loss of speed signal	Shutdown	Engine speed

All fault circuits may be user field programmed for different control functions however their designated fault function is not programmable. Refer to the programming instructions for further information.

PM047 Rev 13 05/03/30

24

Thomson Technology