Usage:
Introduction
This section contains general installation instructions for the Load Sharing Module. Environmental precautions and location considerations are included to determine the best location for the Load Sharing Module. Additional information includes unpacking instructions, electrical connections, and an installation checkout procedure.
Unpacking
Before handling the Load Sharing Module, read page 4, Electrostatic Discharge Awareness. Be careful when unpacking the Load Sharing Module. Check the unit for signs of damage such as bent or dented panels, scratches, and loose or broken parts. Notify the shipper of any damage.
Location Considerations
Consider these requirements when selecting the mounting location:
- * Adequate ventilation for cooling
- * Space for servicing and repair
- * Protection from direct exposure to water or to condensation-prone environment
- * Protection from high-voltage or high-current devices, or devices which produce electromagnetic interference
- * Protection from excessive vibration
- * An ambient operating temperature range of -40 to +70°C (-40 to +158°F)
- * All wiring to/from the Load Sharing Module should be limited to 30 m (98 ft) in length
- * Space for servicing and repair
Do not mount the Load Sharing Module on the engine.
Figure 1-2 is an outline drawing of the Load Sharing Module. Install the unit near the electromagnetic engine control. It may be installed in any position.
To maintain compliance with CE marking requirements, the European Union Low Voltage Directive requires that the Load Sharing Module (LSM) be mounted in an IP43 enclosure as defined in EN60529. Access to the Load Sharing Module must be restricted to qualified personnel.
General Wiring Requirements
The circled ground symbol identifies the Protective Earth Terminal. This terminal must be connected directly to protective earth using a grounding conductor at least as large as those used on terminals 1 through 9. The insulation of the grounding conductor must be of green and yellow color.
This symbol identifies functional or EMC earth. This terminal is to be used for cable shield connections only. It is not to be used as a protective earth terminal.
External wiring connections and shielding requirements for a typical installation are shown in the plant wiring diagram. Figure 1-3. These wiring connections and shielding requirements are explained in more detail in this chapter.
To maintain compliance with CE marking requirements, the Low Voltage Directive requires that the Load Sharing Module must only be connected to Class III equipment.
Wiring for the Load Sharing Module must be suitable for at least 90°C (194°F) and also be suitable for the maximum installed operating temperature.
The Load Sharing Module must be permanently connected and employ fuses or circuit breaker in each of the PT lines to limit current to LSM PT inputs to no more than 5 A. In addition, a 2 A fast-acting fuse or circuit breaker must be provided in the 24 Vdc power supply line.
All terminal block screws must be tightened to 0.56 to 0.79 N·m (5.0 to 7.0 lb-in).
To maintain compliance with CE marking requirements, the EMC Directive requires that all shields be connected to the terminals provided per the plant wiring diagram, Figure 1-3.
Wiring for the Load Sharing Module should not exceed 30 m (98 ft) in length. If any signal run must exceed this limit, an isolator must be used within 30 m of the Load Sharing Module. The isolator must provide galvanic isolation via optical or magnetic means.
Power Requirements
The Load Sharing Module is powered from a 24 Vdc source. The 24 Vdc source must be a minimum of 18 Vdc and a maximum of 32 Vdc continuous. If a battery is used for operating power, an alternator or other battery charging device is necessary to maintain a stable supply voltage.
 |
CAUTION-BATTERY To prevent possible serious damage to the Load Sharing Module, make sure the alternator or other battery charging device is turned off or disconnected before disconnecting the battery from the unit. |
 |
Shielded Wiring
All shielded cable must be twisted conductors with either a foil or braided shield. Do not attempt to tin (put solder on) the braided shield. All signal lines should be shielded to prevent picking up stray signals from adjacent equipment. Wire exposed beyond the shield must be as short as possible.
The other end of the shields must be left open and insulated from any other conductor. Do not run shielded signal wires with other wires carrying large currents. See Appendix C, EMI Control in Electronic Governing Systems, for more information.
Where shielded cable is required, cut the cable to the desired length and prepare the cable as instructed below and shown in Figure 2-1.
Figure 2-1. Preparation of Shielded Cables
- 1. Strip outer insulation from both ends, exposing the braided or spiral wrapped shield. Do not cut the shield on the end nearest the Load Sharing Module. Cut off the shield on the end away from the unit.
- 2. Use a sharp, pointed tool to carefully spread the strands of the shield.
- 3. Pull the inner conductors out of the shield. Twist braided shields to prevent fraying. The breakout length of the shield braid should be 51 mm (2 inches) or less.
- 4. Connect lugs to the shield and to the control wires. Number 6 slotted or round crimp-on terminals for most installations. Connect the wires to the appropriate terminals on the module.
- 2. Use a sharp, pointed tool to carefully spread the strands of the shield.
Installations with severe electromagnetic interference (EMI) may require shielded wire run in conduit, double shielded wire, or other precautions.
General Connections
NOTE: NOTE
Use 1 mm2 (18 AWG) or larger wire for all PT and CT connections.
The spacing between the lugs on terminals 3 and 4 must be 6.5 mm (0.256 inch) or greater to comply with the European Union Low Voltage Directive (see Figure 1-3). The lugs must have insulated sleeves.
NOTE: IMPORTANT
Connections from the potential transformers and current transformers must be made correctly in regard to the three phases for the Load Sharing Module to operate correctly. Sorting out the three phases at the module is tedious and requires numerous generator starts and stops. If at all possible, make sure that the wiring is correctly done at the same time of installation and the phases correctly and permanently identified at the generator and at the module.
Connect the PT output from the A leg to terminal 1. Connect the PT output from the B leg to terminal 2. Connect the PT output from the C leg to terminal 3. Size the potential transformers to produce 100-240 VAC.
Current Transformers
Power source current transformers should be sized to produce 5 A secondary current with maximum generator current (3-7 A secondary current at full load is acceptable). CT burden is 0.1 VA. To prevent lethal high voltage from developing on leads to the terminals, the Load Sharing Module contains internal burden which must be connected across the power source current transformers whenever the unit is running. Ammeters may be installed on the leads from the current transformers.
Connect phase "A" CT to terminals 4 and 5. Connect phase "B" CT to terminals 6 and 7. Connect phase "C" CT to terminals 8 and 9. Observe correct phasing as shown in the plant wiring diagram, Figure 1-3.
Load Sharing lines, Droop, and Auxiliary Contacts
The droop contact for selecting droop or isochronous operation is wired in series with the circuit breaker auxiliary contact between terminals 13 and 14. When both the droop contact and circuit breaker auxiliary contact are closed, the Load Sharing Module is in the isochronous and load sharing mode. In this mode the internal load-sharing-line relay is energized, the droop signal is disabled, and the load matching circuit is connected to the load-sharing lines, permitting isochronous load sharing.
- The Load Sharing Module is in the droop mode when EITHER the droop contact of the circuit breaker auxiliary contact is open. If the droop contact is open, the Load Sharing Module remains in the droop mode even when the circuit breaker auxiliary is closed. If droop is not desired when the auxiliary contact is open, turn the droop potentiometer fully counterclockwise.
Use a single pole, single-throw switch with a 0.1 A minimum rating for the "open for droop" switch.
Use twisted 0.5 mm2 (20 AWG) or larger wire to connect the load sharing lines to the other Load Sharing Modules. Connect the (+) wire from the other Load Sharing Modules to terminal 10. Connect the (-) wire from the other Load Sharing Modules to terminal 11. Connect the shield of the load share wiring to terminal 12. The shield should always connected only to terminal 12. No other shields should be connected to this terminal.
Output to the Caterpillar Digital Electronic Control
Use twisted 0.5 mm2 (20 AWG) or larger shielded wire to connect the pulse-width modulated output signal from load terminals 19(+) and 20(-) to the Caterpillar control. Connect the shield to terminal 21 only. Do not connect the shield at the Caterpillar control end of the wiring.
Synchronization Connections
If an SPM-A synchronizer is used, connect twisted-pair 0.5 mm2 (20 AWG) or larger shielded wire from the synchronizer to terminals 24(+) and 25(-). Tie the shield to terminal 21. Do not connect the shield at the end of the wiring.
Speed Trim Potentiometer
If a speed-trim potentiometer is used, connect a 10 k ohm 10-turn potentiometer to terminals 26 (CW), 27 ( wiper), and 28 (CCW). Use 0.5 mm2 (20 AWG) or larger wire and connect the shield to terminal 21. Do not connect the potentiometer end of the shield. The potentiometer is used to move the speed setting when manually synchronizing the generator or to change load demand in droop mode. If no potentiometer is used, add a 10 k ohm resistor between terminals 26 and 28.
NOTE: NOTE
Shielded output lines should be limited to 30 m (98 ft) maximum length.