The generator set that is used in rental, public services, construction or other applications, in which the gen set must perform multiple functions, should be easy and safe to operate in order to adapt to the actual work that it must perform at any given time.

INMESOL has developed a new range of control units for multipurpose generator sets based on the DSE 8620 MKII or the DSE 8920, where the functions from DSE 8620MKII or DSE 8920 can be easily switched to DSE 8610 MKII or DSE 8910 functions from a single control unit.

Changing applications and from some features to others is very easy with the control unit’s selectors and potentiometer.

Note: For any application and operation of the generator set, the OFF/ON selector must be on the ON position (position I).

Possible applications of a generator set(s) with a MULTIFUNCTION control unit

A generator set with a MULTIFUNCTION control unit can work in any of these applications:

DSE 8610 MKII Features

1. Manual generator set in island mode with remote start up or external signal start up.

The operation of the manual generator set in island mode is the most basic configuration in the control unit, and used when there is no mains or other generator sets present. The generator set receives an external signal, which closes a contact and produces the start up. After a few seconds, the gen set parameters will be within the accepted levels, and the generator switch will close, thus powering the load. When the signal is removed the unit’s circuit breaker opens and the engine stops after a period of cooling.

2. Generator set in parallel with the mains by exporting a fixed power to the mains.

In this application, the generator set exports electric power to the mains, when it requires input.

The generator set is connected to the mains and the parallel selector is switched to the ON position. The start up signal of the generator can be entered manually or by means of a remote signal.

By starting the unit manually and, after a few seconds, pressing the Close gen set button, the unit synchronises with the mains and the circuit breaker closes.

Initially, the generator set delivers a minimum power that will increase until reaching the power set with a potentiometer, the ‘POWER’.

Pressing the Mains control button, the power of the unit decreases until reaching a minimum power and then opens the circuit breaker. After a cooling period, the engine shall be stopped.

If the unit is started through a remote signal, the same sequence that is manually performed will be automatically executed, as well as when the signal disappears.

3. Generator set in sync with other generator sets with shared load.

This occurs when a load is shared by several generator sets who are mutually synchronised and each assumes an established load distribution, starting and stopping according to the load demand. Gen sets can be configured to alternate their service.

With the same basic configuration in parallel mode with the mains, all generator sets are connected to a common bus or bar. In turn, the generator sets are connected to each other by a communications cable (MSC Net).

DSE 8620 MKII Features

4. Generator set to mains stand by operation with uninterrupted return to the mains.

• With external switching

In this mode, the control unit of the generator set controls the external switching, detects when a failure occurs in the mains, and starts the engine. Once started, and while having all its parameters within the previously established limits, the control unit sends orders to open and shut the unit’s external switching contactors and motorised thermal magnetic breakers (without mechanical interlock) respectively, so as to change the supply from the mains to the generator set. When the mains is restored, the control unit enables the change of supply from the generator set to the mains, thus enabling synchronism with the main network for a few seconds. The set gradually reduces the delivered load, and then opens the contactor or circuit breaker for Gen, and the engine stops after a period of cooling.

• ‘Half a commutation’

The configuration above can be changed by programming the control unit so that the circuit magnetic breaker of the Gen set also functions as a Gen set switch. The external mains switch is controlled by the control unit of the generator set. In the event of a mains failure, the generator set behaves in the same way as with a complete switch.

5. Generator set that export a fixed load to the mains with a stand-by function in case of mains failure.

Several of the applications mentioned above can be combined. The selector in the “Export” position 0 work mode activates the generator set that exports to the mains a fixed amount of power according to the established schedule, the amount of power, and the supply time. Besides, it remains in a stand-by mode in case of mains failure. The fixed amount of power generated by the gen set (green area) and exported to the mains is established by a potentiometer.

Note.- The green area corresponds to the power supplied by the gen set and the blue area corresponds to the power supplied by the mains.

6. Generator set in stand-by mode when the mains experience consumption peaks or a failure in the mains supply.

Another application of this equipment is the operation in support or stand-by mode to the mains for specific situations in which there is a consumption peak and the mains do not have enough supply capacity. In this case, put the selector in the “Peak-Shaving” position I mode. In this position, the function of the potentiometer consists of setting the amount of power for activating the generator set to supply surplus power required by the load. Besides, it remains in a stand-by mode in case of mains failure.

Note.- The green area corresponds to the power supplied by the gen set and the blue area corresponds to the power supplied by the mains.

GENERATOR SET OPERATION TESTS with load from an installation

In order to test the generator set operation in one of these installations, two operation modes have been established:

1. By simulating a mains failure, the generator set is synchronized with the mains. They remain parallel for a few seconds and then, the gen set takes on the installation load during the test, disconnecting the mains.

Therefore, put the TEST MODE selector in position I and the PARALLEL selector in position I.

When the test is finished, the TEST MODE selector is put in the 0 mode and the mains is automatically connected again, remaining in parallel with the gen set for a few seconds and taking on the installation load. The gen set reduces power supply until it stops, remaining again as a stand-by with the mains and/or the feature that it had before the test.

2. The generator set must be synchronized with the mains and work in parallel with it, exporting an “artificial” load selected by the potentiometer.

Therefore, select the fixed amount of power for carrying out the test using the potentiometer, put the TEST MODE selector in position II and the PARALLEL selector in position I.

When the test is finished, the TEST MODE selector is switched to the 0 mode. The gen set reduces power supply until it stops, remaining again as a stand-by with the mains and/or the feature it had before the test.

The combination of two or more generator sets with this type of unit provides a number of sophisticated features such as:

• 2 Gen sets in sets in Mutual Stand by with each other.

• 2 Gen sets in sets in Mutual Stand by with each other, and both in stand-by with the mains.

• Two or more generator sets in stand-by with the mains and in parallel with the mains.