Mecc Alte DER1 User manual

DER1 digital regulator instruction manual - rev. 05 - pag. 2
INDEX pag. 2
INTRODUCTION
pag. 3
MAIN CHARACTERISTICS pag. 3
1. Architecture of the system pag. 3
1.1 Regulator pag. 3
1.2 Communications module pag. 3
2. Technical Characteristics pag. 4
3. Inputs and Outputs: technical specifications pag. 5
4. Block diagram pag. 6
INSTALLATION pag. 7
1. Overall dimensions drawings pag. 7
2. Connections pag. 8
3. Terminals pag. 8
4. DER1 connections pag. 8
4.1 Connections based on voltage pag. 8
4.2 DER1 connections for typical applications pag. 9
5. Setting up the regulator pag. 9
5.1 Alternator voltage signals pag. 9
5.2 Calibrating sensing pag. 9
6. 50/60 Signal pag. 9
7. APO Contact pag. 9
8. Remote control of voltage pag. 16
9. VOLT, STAB,Hz and AMP Trimmers pag. 17
10. Serial communications pag. 17
PARAMETERS AND OPERATING DATA pag. 18
1. ModBus registry list pag. 18
2. Word of configuration (Parameter P[10]) pag. 18
3. RAM location reference, activation of saturation in analog remote control pag. 19
4. Volatile memory addresses pag. 20
5. Fourth Status Word (Location L[39]) pag. 20
SETTING OF VOLT, STAB, AMP and Hz PARAMETERS pag. 21
1. Voltage pag. 21
1.1 Setting voltage pag. 21
1.2 Soft Start pag. 21
1.3 Slow voltage variations pag. 22
2. Stability pag. 22
2.1 Adjustment of stability pag. 22
3. Excitation overcurrent pag. 26
3.1 Description pag. 26
3.2 Calibration with a supervision unit pag. 27
3.3 Calibration without a supervision unit pag. 27
4. Underspeed pag. 27
4.1 Description pag. 27
4.2 Calibration with a supervision unit pag. 28
4.3 Calibration without a supervision unit pag. 28
5. Underspeed pag. 29
6. Other parameters pag. 29
6.1 Vout / Vaux Ratio pag. 29
6.2 V/F slope at start up pag. 29
6.3 Short cirrcuit time pag. 29
CONTROLLING OF REGULATOR ALARMS pag. 30
1. Alarm signals with the indicator lights pag. 30
2. Description of alarms pag. 31
3. APO Output pag. 32
4. Board operation time pag. 32
APPENDIX pag. 33
DER1 Digital Regulator

DER1 digital regulator instruction manual - rev. 05 - pag. 3
The information contained in this manual may be modified without advance notice.
This revision supersedes and replaces all previous editions.
Even partial reproduction of this manual is prohibited, with any means whatsoever, without prior written
authorisation by Mecc Alte S.p.A.
INTRODUCTION
This manual contains information on the operation and use of the DER1 digital regulator.
MAIN CHARACTERISTICS
1. Architecture of the system
The DER1 is a voltage regulator for synchronous alternators, designed for stand alone working and
calibration; to maximize performances, the regulator should be intended as part of a system made up of at
least three components: the DER1 (control unit), a communications module (USB2DxR, for example) and
a supervision unit, as illustrated in figure 6.
The connectors for connection to and from the power generator and communications module are located
on the DER1 regulator.
The supervision unit can be made up of a personal computer, another “synoptic” device or both; it does
not have the function of controlling the system in real time, but allows programming and visualisation of all
operational parameters of the DER1.
If it is equipped with USB interface, it’s possible to use the USB2DxR communications module for its
connection.
1.1 Regulator
Since the regulator is designed to control many different types of generators, it must be appropriately
configured to obtain the best performance; most of the settings are stored in a non-volatile integrated
memory (EEPROM). The first time the regulator is turned on, a default configuration will be present, which
satisfies the most widely requested characteristics and is suitable to facilitate installation: the trimmers are
active and the inputs for the external potentiometer and the 60 Hz jumper are enabled, therefore the basic
calibrations can be performed without the use of additional equipment.
Two versions of the DER 1 and DER 1/A regulators are available; the first one is optimised for Mecc Alte
Series 3 to 38 alternators, while the second is optimised for Mecc Alte series 40, 43 and 46 alternators; the
two versions differ primarily in the default parameters.
NOTE: the parameter that defines the output voltage (with the VOLT trimmer disabled) is set on 0 (so that
the adjustment takes place on the minimum voltage).
1.2 Communications module
The USB2DxR communications module (which is provided for connection to the COM connector of the
DER1) is equipped with a USB port, through which it is possible to set the parameters (for both
configuration and operation) and “monitor” operation of the generator.
In order to avoid damage to persons and/or property, only qualified personnel, having full
knowledge and understanding of the information contained in this manual, should perform the
procedures described herein; when power to the unit is on, the voltage present may be lethal for
the operator.
All connections must be made with the power off.
The plastic protections on connectors J1 and J2 must not be removed for any reason whatsoever.

DER1 digital regulator instruction manual - rev. 05 - pag. 4
2. Technical Characteristics of the device installed on board
• Digital controlled regulator, based on DSP
• Suitable for all Mecc Alte self-regulated alternators
• Power connections through 20 poles(1) Fast-On connector (see fig.2)
• Protection of power winding with 5A fast acting fuse
• Signal connections (Pext, 60Hz Jumper, APO) through 10 poles mini Fast-On separate connector
• Environmental temperature: -25°C ÷ +70°C
• Voltage supply: 40Vac÷270Vac (2)(from auxiliary winding, output voltage or PMG)
• Maximum continuous output current: 5Adc
• Frequency range: 12Hz÷72Hz
• Three phase or single phase sensing in all connections (Y--YY-)
• Single phase or three phase sensing automatic recognition
• Average value of voltage regulation
• Voltage regulation range (sensing) from 75Vac to 300Vac
• Precision of voltage regulation: ± 1% from no-load to nominal load in static condition, with any power
factor and for frequency variations ranging from -5% to +20% of the nominal value.
• Precision of voltage regulation: ± 0,5% in stabilized conditions (load, temperature).
• Transient voltage drop and overvoltage within ± 15%
• Voltage recovery time within ± 3% of the value set, in less than 300 msec.
• Programmable Soft start
• Parameters: VOLT, STAB, AMP and Hz settable by trimmers (default), 50/60Hz settable by a
“jumper” (default), all parameters programmable via software
• 0÷2,5Vdc or -10÷+10Vdc external voltage for analogical remote control of output voltage
• Remote control of output voltage through external potentiometer (from 25Kohm to 100Kohm)
• Underspeed protection with adjustable threshold and slope
• Overvoltage and undervoltage alarms
• Excitation overcurrent protection with delayed intervention
• Underexcitation alarm/loss os excitation(6)
• Management of temporary short circuits (start up of asynchronous motors)
• Open collector output (not insulated) signalling some allarm intervention with programmable activation in
respect of each alarm and possibility of the intervention delay and selectable active level(6)
• Allarm conditions storage (type of alarm, number of events, duration of the last event, total time)
• Memorization of the regulator operation time
• USB communications interface (with optional USB2DxR module)
WARNING : Operation of the DER1 is not specified below 12 Hz.
NOTE (2) : with EMI external filter SDR 128/K, see Fig.4 (3m without EMI filter)
NOTE (6) : Starting from rev. 19 of the firmware

DER1 digital regulator instruction manual - rev. 05 - pag. 5
3. Inputs and Outputs: technical specifications
TABLE 1 : CONNECTOR CN1
Terminal(1) Name Function Specification Notes
1 Exc- Excitation Continuous Rating: 5Adc
Transitory Rating:12Adc at peak
2 Aux/Exc+
3 Aux/Exc+ Power 40÷270 Vac, Frequency: 12÷72Hz(2) (1)
4 UFG Sensing
Range 2 Range 2: 150÷300 Vac Burden: <1VA U channel
5 UFG
6 UHG Sensing
Range 1 Range 1: 75÷150 Vac Burden: <1VA
7 UHG
8 UHB Jumper
Range1 Short for sensing 75÷150 Vac
9 UFB
10 UFB
Board reference
11 UFB
12 UFB
13 - Not present
14 VFG Sensing Range 1: 75÷150 Vac
Burden: <1VA V channel, to be
connected in parallel to
U channel in case of
single phase sensing
15 VHG Sensing
Range 1
16 VHB Scala 2: 150÷300 Vac
Burden: <1VA
17 VFB Range 2
18 - Not present
19 WFG Sensing Range 1: 75÷150 Vac
Burden: <1VA W channel, unused
(with shorted inputs)
in case of single phase
sensing
20 WHG Sensing
Range 1
21 WHB Range 2: 150÷300 Vac
Burden: <1VA
22 WFB Range 2
Star point (12 YY or 6 Y leads
generators) is hard connected
to AVR power supply input (1)
TABLE 2 : CONNECTOR CN3
Terminal Name Funcion Specifications Notes
23 Common
Active
protections output
Type: Non-insulated open collector
Current: 100mA
Voltage: 30V
Max length: 30m (3)
Programmable : active
level(6), activating alarm
and delay time
24 A.P.O.
25 Common Jumper 50/60Hz Type: Not insulated
Max length: 3m Selection of underspeed protection threshold (4)
26 50/60Hz
27 0EXT Jumper for remote voltage
control 0÷2,5Vdc Type: Not insulated Max length: 3m Short for 0÷2,5Vdc input or potentiometer
28 JP1
29 Input for remote voltage Type: Not insulated
Max length: 30m (3) Regulation: ±10 % (5)
Input for remote voltage
control 0÷2,5Vdc or Pext
30 PEXT Input:0÷2,5VdcoPotentiometer100K Burden: 0÷1mA (sink)
31 JP2 Pext Jumper Type: Not insulated
Max length: 3m Short for 0÷2,5Vdc input or potentiometer
32 ±10V control ±10 Vdc Input: ±10Vdc Burden: ±1mA (source/sink)
0EXT
Note 1) The terminals are connected to each other on the board: 2 with 3, 4 with 5, 6 with 7, 9 with 10, 11 and 12.
Note 2) Minimum power voltage 40 Vac at 15 Hz, 100 V at 50 Hz, 115 V at 60 Hz
Note 3) With external EMI filter 182/K (3m without EMI filter)
Note 4) 50·(100%-αHz%) or 60·(100%-αHz%) where αHz% is the position relative to the Hz trimmer or the percen
tage value of parameter P[21]
Note 5) Value not to be exceeded. The effective range depends on parameter P[16]
Nota 6) Starting from revision 19 of the firmware

DER1 digital regulator instruction manual - rev. 05 - pag. 6
4. Block diagram
Name Function Notes
VOLT Voltage Calibration From 75Vac to 150Vac or from 150Vac to
300Vac, see paragraph “Setting the voltage”
STAB Calibration of dynamic response Adjustment of proportional gain, see paragraph
on “Stability”.
Hz Calibration of underspeed protection
intervention threshold Variation up to -20% with respect to the nominal speed value set in parameter 50/60.
AMP Calibration of excitation overcurrent
protection See paragraph “Calibration of excitation overcurrent protection”
TABELLA 3: TRIMMERS
Fig 1
INSTALLATION
Upon receipt of the digital regulator, perform a visual inspection to ensure that no damage has been
sustained during transportation and movement of the equipment. In the event of damage, advise the shipper,
the insurance company, the seller or Mecc Alte immediately. If the regulator is not installed immediately,
store it in its original packaging in a dust and humidity-free environment.
The regulator is normally installed in the generator terminal box. It is fixed with two M4x25 screws and must
be installed in a location where the temperature does not exceed the environmental conditions foreseen. The
regulator is equipped with a 5A fast-acting protection fuse. If necessary, the fuse must be replaced only wiith
a fuse of the same type and rating.

DER1 digital regulator instruction manual - rev. 05 - pag. 7
1. Overall dimensions drawings
dimensions in mm Fig 2
2. Connections
The digital regulator connections depend on the application and excitation system.
Figure 1 shows the functional aspect of the connection points to the regulator
An error in connection may have deadly consequences for the unit.
Carefully check to make sure that all connections are precise and in accordance with the attached drawings,
before turning on the power.

DER1 digital regulator instruction manual - rev. 05 - pag. 8
3. Terminals
Figures 1 and 2 show the connection terminals; the connections must be made using cables having a
minimum diameter:
 1,5 mm² for power cables on terminals from 1 to 22
 0,5 mm² for signal cables on terminals from 23 to 32
4. DER1 connections
The DER1 regulator has 3 differential inputs, with 2 selectable scales for each of them (see fig. 1):
 scale "H" for voltages between 75V and 150V
 scale "F" for voltages between 150V and 300V
4.1 Connections based on main alternator voltage
Based on the machine connections, and the desired voltage(1) you can use the three phase or single
phase sensing used in one range or the other. Table 4 summarises the connections for the most common
voltages.
TABLE 4: ALTERNATOR VOLTAGE AND SENSING CONNECTION
Connection Phase-to-Phase Voltage [V] Sensing - Phase Range Drawing Notes
Series star
Single phase on half phase H SCC0160/02
Three phase on half phase H SCC0158/04
Single phase on full phase F N.A.
Three phase on full phase F N.A.
530-550-575-600-690-760-
800-920-960(from 520 to 1000) Single phase on half phase F SCC0161/02
Three phase on half phase F SCC0159/04
1200 (from 1100 to 2000) Single phase on half phase F SCC0202/00 2 channels in
series
Parallel star
190-200-208-220-230-240-
250 (from 130 to 250) Single phase H SCC0160/02
Three phase H SCC0158/04
380-400-415-440-460-480-
500 (from 260 to 500) Single phase F SCC0161/02
Three phase F SCC0159/04
Series delta
220-230-240-254-265-277-
290 (from 150 to 300) Single phase on half phase H SCC0160/02
Three phase on half phase H SCC0158/04
305-320-330-440-460-530-
555 (from 300 to 600) Single phase on half phase F SCC0161/02
Three phase on half phase F SCC0159/04
220-230-240-254-265-277-
290 (from 150 to 300) Single phase on full phase F N.A.
Three phase on full phase F N.A.
Parallel delta
110-115-120-127-133-138-
145 (from 75 to 150) Single phase H SCC0160/02
Three phase H SCC0158/04
152-160-165-220-230-265-
277 (from 150 to 300) Single phase F SCC0161/02
Three phase F SCC0159/04
Zig-Zag(2) 330-346-360-380-400-415-
430 (from 260 to 500)
Single phase on full phase F N.A.
Three phase on full phase F SCC0203/00 2 channels in
series
Single phase
parallel
220-230-240-254-265-277-
290 (from 150 to 300) Single phase - Partial H SCC0160/02
Single phase - Complete F N.A.
305-320-330-440-460-530-
555 (from 300 to 600)
Single phase - Partial F SCC0161/02
Single phase - Complete F N.A. 2 channels in
series
380-400-415-440-460-480-
500 (from 260 to 500)
(1) Compatibly with the rated characteristics of the alternator
(2) Sensing only on full phase

DER1 digital regulator instruction manual - rev. 05 - pag. 9
4.2 DER1 connections for typical applications
Drawings SCC158/04, SCC159/04, SCC160/02, SCC161/02 show DER1 regulator connections for typical
applications.
In case of sensing 75V-150V, with half-phase reference the typical drawing for three-phase connection is
SCC158/04, while for single phase it is SCC160/02.
In case of sensing 150V-300V, with half-phase reference the typical drawing for three-phase connection is
SCC159/04, while for single phase it is SCC161/02.
5. Setting up the regulator
Selection of the sensing scale takes place directly according to the connection on the power terminal
board; additional settings can be made with 4 trimmers (VOLT, STAB, AMP and Hz) and 3 jumpers
(50/60Hz, JP1 and JP2); the output voltage can also be set with an external analogical signal; additional
settings, including the previous ones but excluding jumpers JP1 and JP2, can be made by modifying the
25 parameters stored in a non volatile integrated memory.
5.1 Alternator voltage signals
Terminals 4-22 of connector CN1 are used for voltage sensing.
5.2 Calibrating sensing
A supplementary calibration may be necessary to compensate any existing tolerances on analogical
voltage acquisition channels; in this case follow the procedure illustrated below.
1. Write 16384 at location 19 (from the Settings/Advanced(1) Menu)
2. Disable VOLT trimmer (from the Settings/Potentiometers(1) Menu)
3. Disable Vext (from the Settings/Advanced(1) Menu)
4. The parameter present in parameter P[5](if three phase sensing) or p[6] (if single phase sensing)has to
be calibrated. Calibration should be adjust in order to obtain 225V from the generator output when the
sensing is cabled to UFB (9-10-11-12) and UFG (6-7), or to 125.5V if connected UFB (9-10-11-12) and
UHG (6-7).Please note that a paramenter increment will result in a voltage reduction of the system. It is
recommended to measure the voltage output with an instrument capable to catch the average value of
the voltage.
5. In order to ensure that the value of voltage (available also at location 36) is the same as the value
measured at point 6, calibrate the data at location 7, reading the value of Volt box in the “status” area of
Settings/Advanced (1) menu..
6. Enable the trimmers again, if it is desired to have them active (from the Settings/Potentiometers(1)
menu).
7. Enable Vext (from the Settings/Advanced(1) Menu) if you want to be active.
6. 50/60 Signal
A jumper is located on the 50/60 input (terminals 25 and 26); if enabled from the Configuration Menu, it
provokes the commutation of the underspeed protection threshold from 50·(100%-αHz%) to 60·(100%-
αHz%), where αHz% represents the position relative to the Hz trimmer or the percentage value entered at
parameter [21 (where 10% corresponds to 16384).

7. APO Contact
The acronym APO stands for Active Protection Output: (connector CN1 terminals 23 and 24) 30V-100mA
non-insulated open collector transistor, normally closed, if the “APO Invert” flag (2) is active (default), opens
(with a delay that can be programmed from 1 to 15 seconds) when, of all the alarms, one or several sepa-
rately selectable alarms are active.
NOTE (1) : Software DxR Terminal
NOTE (2) : Starting from rev. 18 of the firmware, if the “APO Invert” flag is not active or for firmware revisions up to 17 the transistor
is normally open and it closes in case of an active alarm

DER1 digital regulator instruction manual - rev. 05 - pag. 10
SCC0158/04: Three phase sensing 75V-150V

DER1 digital regulator instruction manual - rev. 05 - pag. 11
SCC0159/04: Three phase sensing 150V-300V

DER1 digital regulator instruction manual - rev. 05 - pag. 12
SCC0160/02: Single phase sensing 75V-150V

DER1 digital regulator instruction manual - rev. 05 - pag. 13
SCC0161/02: Single phase sensing 150V-300V

DER1 digital regulator instruction manual - rev. 05 - pag. 14
SCC0202/00: Single phase sensing 300V-600V

DER1 digital regulator instruction manual - rev. 05 - pag. 15
SCC0203/00: Single phase sensing 300V-600V
(generator in threephase ZIG-ZAG connection)

DER1 digital regulator instruction manual - rev. 05 - pag. 16
Figure 3a: without saturation of the output voltage
upon reaching the input voltage limits. Figure 3b: with saturation of the output voltage upon reaching the input voltage limits.
TABLE 5: HARDWARE AND SOFTWARE CONFIGURATION OF VOLTAGE REMOTE CONTROL
Jumpers
JP1 (27-28) JP2 (31-32) RAM Voltage CTRL Ext. Input
Potentiometer 0Ext - Pext (29-30) Close Close Disabled (Bit B7=0) Enabled (Bit B12=1)
0V/2,5V without saturation 0Ext - Pext (29-30) Close Close Disabled (Bit B7=0) Enabled (Bit B12=1)
0V/2,5V with saturation 0Ext - Pext (29-30) Close Close Enabled (Bit B7=1) Enabled (Bit B12=1)
-10V/+10V without saturation 0Ext - ±10V (29-32) Open Open Disabled(Bit B7=0) Enabled (Bit B12=1)
-10V/+10V with saturation 0Ext - ±10V (29-32) Open Open Enabled (Bit B7=1) Enabled (Bit B12=1)
Parameter P[15] EEPROM Close Close Disabled(Bit B7=0) Disabled (Bit B12=0)
Location L[49] RAM Close Close Enabled (Bit B7=1) Disabled (Bit B12=0)
Flags ( configuration menu) or Parameter P[10]
Type Input
With a 100Kohm linear potentiometer connected as shown in figure 4a, you have the full excursion set
with parameter P[16] (with the default value P[16]=4608 there is an excursion of ± 14%); with a 25Kohm
linear potentiometer in series with a 3.9Kohm resistor, connected as shown in figure 4b, the effect of the
external potentiometer is cut in half (with the default value P[16]=4608 there is an excursion of
approximately ± 7%).
8. Remote control of voltage
The Pext input (terminal 30) and ±10V (terminal 32) allow to obtain remote control of the output voltage by
means of a DC signal or an external potentiometer. The output voltage can be controlled by software as well
with the P[19]. The excursion range and gain of the remote control can be set independently by software
despite the output voltage control device system used (potentiometer, VDC signal or P[19]). If DC voltage is
used, it will take effect if it is within the range 0Vdc/2,5Vdc or -10Vdc/+10Vdc, when connected between
terminals 30 and 29 and subjected by jumpers JP1 and JP2; for values exceeding the aforementioned limits
(or in the event of disconnection), two options are possible: not to take the set point of external input and
return to regulation to the voltage value set with the trimmer (if enabled) or with parameter P[19], or keep the
minimum (or maximum) value of voltage that can be reached (see figures 3a and 3b). The two options can be
set with the RAM Voltage CTRL flag in the Settings/Advanced menu corresponding to the bit B7 of the
configuration word P[10] (see PARAMETERS AND OPERATIONAL DATA - Para. 2). The setting relative to
the Vext input are summarised in table 5.
NOTE: the source of DC voltage must be capable of absorbing at least 2 mA.
In making adjustments it is reccomended not to exceed the nominal value of voltage of the alternator beyond
± 10%
Relationship between analogical input and output voltage

DER1 digital regulator instruction manual - rev. 05 - pag. 17
Fig. 4a: 100K external potentiometer connection Fig. 4b: 25K external potentiometer connection
9. VOLT, STAB, Hz and AMP Trimmers
The trimmers are enabled by the software DxR_Terminal; if they are not enabled, they do not perform any
function.
The VOLT trimmer allows adjustment from about 75V to about 150V or from about 150V to about 300V.
The STAB trimmer adjusts the dynamic response (statism) of the alternator under transient conditions.
The Hz trimmer allows for a variation of the "low speed protection" of up to –20% with respect to the
nominal speed value set by the 50/60 jumper (if activated) or by the 50/50 box in the Settings/
UFLO&LAM menu (at 50 Hz the threshold can be calibrated from 40 Hz to 50 Hz, at 60 Hz the threshold
can be calibrated from 48 Hz to 60 Hz).
The AMP trimmer adjusts the excitation overcurrent protection intervention threshold.
10. USB Communications
The COM connector is RESERVED for connection to the USB2DxR communications module through the
dedicated cable provided together with the module (see fig. 6).
For the communication, the regulator implements a subsystem of the ModBus standard; the DER1-
USB2DxR system performs a “slave” operation the address of which is stored in the DER1 EEPROM and is
set during configuration.
Detailed descriptions of the ModBus commands implemented are into the Technical Guide “Digital Regula-
tors Comunication Protocol” available on the web site www.meccalte.com.
The “Master Unit” is made up of a PC or other dedicated equipment and can access the parameters and
functions of the regulator.
The master unit has the following possible functions:
 Repetition, or visualisation, of the generator status variables, even from a remote location
 Setting of single parameters
 Uploading and downloading of settings files
 Status readings (alarms, measuring variables)
 Readings of the alarm memory information
Fig. 5: Connessione filtro EMI SDR182/K Fig. 6: Connessione tra DER/1 e PC tramite interfaccia digitale USB2DxR

DER1 digital regulator instruction manual - rev. 05 - pag. 18
TABLE 6 : EEPROM SETTING REGISTRIES
Add. Description of Parameter Range NOTES
DER1 DER1/A
0 Firmware revision 0..65535 19 19 Reserved - Do not write
1 ModBus slave address 1..31 1 1 Identification of RS485 network (or broadcast)
2 Software configuration 0..65535 16402 18962 Reserved - Do not write
3 Serial number, high part 16bit 0 0 Reserved - Do not write
4 Serial number, low part 16bit 0 0 Reserved - Do not write
5 Three phase sensing calibration 0..32767 16384 16384 Calibration of voltage channels in 3 ph adjustment
6 Single Phase sensing calibration 0..32767 16384 16384 Calibration of voltage channels in 1 ph adjustment
7 Measured voltage calibration 0..32767 16384 16384 Calibration of location L 36 (first “STATUS” box)
8 Current limit time 0..32767 0 0 Duration of limiting in number of periods
9 Current limit level 0..32767 32767 32767 Excitation voltage limit upon start-up
10 Word configuration 16bit 7988 7988 Detailed descriptions paragraph 2 table 7
11 Shift to LEFT proportional gain 0..6 4 5 n=0…6 is equivalent to a multiplication by 2n
12 Shift to LEFT integral gain 0..6 3 1 namely 1, 2, 4, 8, 16, 32, 64.
13 Coefficient tieing Ki to Kp 0..32767 16384 26624 Coefficient to set Ki and Kp separately
14 Vout / Vaux Ratio ±32767 6000 6000 Limit to voltage reduction as a function of frequency
15 Reference equivalent to Vext 0..32767 16384 16384 Value used if the Vext input and location L[49] are disabled
16 Limitation of Vext Variation 0..6553 4608 4608 Limits the effect of external analogical input (0->0; 4608->14%)
17 APO delay & alarm settings 0..65535 254(1) 254(1) Selects alarms that activate the APO contact and sets the delay
intervention
18 Step limitation reference 1..1000 20 20 For rapid variations of voltage setpoint, the passage from one
value to another takes place through added or subtracted steps at
each period.
19 Vout Reference 0..32767 0 0 Value used if the VOLT trimmer is disabled
20 Stability 0..32767 16384 16384 Value used if the STAB trimmer is disabled
21 Freq. threshold 10% freqnom 0..32767 16384 16384 Value used if the Hz trimmer is disabled
22 Excitation overcurrent threshold 0..32767 16384 16384 Value used if the AMP trimmer is disabled
23 V/F Slope 0..32767 9000 9000 V/F curve slope during normal operation
24 V/F curve slope at start up 0..32767 6000 6000 Used only upon start up
25 Short circuit time 0..255 20 20 Operating time with short circuited alternator, expressed in tenths
of seconds (0 ….. 25.5 seconds) [0=excluding STOP]
26 Overspeed threshold ±32767 0 0 Variation (10%) of overspeed alarm intervention with respect to
the default value of 55/66Hz
27 Underexcitation threshold (1)(3) 0..32767 512 512 Under-excitation alarm threshold (1)
28 Ki over-excitement Regulator 0..32767 12287 12287 Integral gain of excitation voltage regulator
29 AMP slope (f) (1) (3) 0..32767 15154 15154 AMP (f) (1)(3) overexcitation protection slope
30 Thermal dispersion coefficient 0..65535 63600 63600 Used by AMP alarm temperature estimator
31 Reserved 0..65535 - - Do not write
Default
PARAMETERS AND OPERATING DATA
1. ModBus registry list
An EEPROM memory is used to store configuration parameters and other information that must not be lost
when the generator goes off. Parameters can be read/written and machine operational settings entered
through USB connections (with module USB2DxR). Two versions of the regulator are available, called
DER1 and DER1/A; they differ primarily in the default value of several parameters. Table 6 shows a
complete list of the parameters that can be set, which define all the operational conditions of the regulator.
Note:Locations are ordered to separate the parameters of individual regulators (S.N:, SW versions and
calibration) from settings foreseen, in order to facilitate programming of regulators with the same settings but
different S.N., SW versions and calibrations. The parameters from 0 to 9 are adjusted at the factory for each
regulator. The parameters from 10 to 30 can therefore be freely copied from one to another.
NOTE (1): starting from rev. 18 of the firmware
NOTE (2): shutdown intervention threshold not to be changed in the versions preceding the 18th
NOTE (3): proportional gain of excitation voltage regulator in the versions preceding the 18th

DER1 digital regulator instruction manual - rev. 05 - pag. 19
Bit Value Function Default
B0 1 Not used 0
B1 2 Periodical reference variation 0
B2 4 Automatic voltage offset compensation(1) 1
B3 8 Not used 0
B4 16 Enable hardware jumper 50/60Hz 1
B5 32 Inversion APO(4) 1
B6 64 Force three-phase sensing 0
B7 128 External location reference L[49] (2) and activation of saturation in the event of overflow(3) 0
B8 256 Enable VOLT TRIMMER 1
B9 512 Enable STAB TRIMMER 1
B10 1024 Enable Hz TRIMMER 1
B11 2048 Enable AMP TRIMMER 1
B12 4096 Enable external analogical input 1
B13 8192 Enable external DAC 0
B14 16384 60 Hz setting in the event of disabling of the 50/50 Hz hardware jumper 0
B15 32768 Reserved 0
TABLE 7 : BIT FUNCTION OF THE CONFIGURATION WORD (PARAMETER P[10] )
3. RAM location reference, activation of saturation in analogical remote control
The RAM Voltage CTRL Flag (corresponding to bit 7 of the P[10] configuration word) performs two
functions:
1. If the Pext hardware input is enabled (Flat Ext. Input corresponding to bit 12 of the P[10] configuration
word), as previously described, the RAM Voltage CTRL Flag activates saturation of output voltage
when the analogical control voltage reaches the limit foreseen for input, to which it is applied (see Para.
8 Remote control of voltage).
If saturation is enabled, in the event of removal of the Vext/Pext connection (due to accidental
opening, for example) the voltage goes to the maximum value set in parameter P[16] (+14% by
default).
2. When Pext is disabled by hardware, the indicated flag defines the value to be used by the software
control of the output voltage. If RAM Voltage CTRL is deactivated (B7=0), the non volatile parameter P
[15] is used (therefore following shut down and restart of the regulator, the last value memorised
remains set): on the start up the location L[49] is initialised with the value of parameter P[15] and is
kept aligned to that value. Editing of location L[49] has no effect in this working condition. If RAM
Voltage CTRL is active (B7=1) the volatile location L[49] is used for software remote control of the
output voltage (when the regulator is energized, the value is stored. If the regulator is shut down, the
value is lost). This function is particularly useful for the applications of alternators in parallel with grid,
when the regulation of the reactive power exchanged is controlled by means of a third party supplied
digital supervisor.
FLAG RAM
Voltage CTRL P[10] Bit B7 FLAG Ext. Input P[10] Bit B12 Output voltage control type
0 1 Analogical without saturation
1 1 Analogical with saturation
0 0 Digital - Parameter P[15]
1 0 Digital - Location L[49]
TABLE 8 : REMOTE VOLTAGE CONTROL FLAGS FUNCTION
2. Configuration word (Parameter P[10])
Configuration of the regulator takes place by setting the individual bits of parameter P[10]. Each of them
enables or disables at least one function, on the basis of the fact that its value is respectively 1 or 0.
If the "DxR Terminal" programme is used (see technical guide “Interface communication USB2DxR"), the
setting is simplified by the use of the dedicated flags in the different menu corresponding to the specific bit
which enables/disables each function.
Alternatively, the DER1 can be configured by directly setting the value of the P[10] parameter; in this case
the value is calculated before entry, summing the numbers indicated in the column "Value" of Table 7,
corresponding to the functions it is desired t enable.
For example, the default configuration calls for the bits B2, B4, B5 and those from B8 to B12 to be enabled.
The corresponding value is therefore: P[10]=4+16+32+256+512+1024+2048+4096=7988.
NOTE (1): only with single-phase reference
NOTE (2): if analogical input is disabled
NOTE (3): for analogical input
NOTE (4): starting from rev. 18 of the firmware

DER1 digital regulator instruction manual - rev. 05 - pag. 20
NOTE (1): depending on the sensing and nominal frequency
NOTE (2): starting from revision 18 of the firmware
NOTE (3): software configuration, with jumper 50/60 disabled
TABLE 10 :STANDARD VALUES OF THE FOURTH STATUS WORD (LOCATION L[39])
Sensing 50Hz 60Hz
Single phase 7988 24372(2)
Three phase 8048(2) 24432(2)
Rated frequency:
Bit Function Value Default
B0 Not used 1 0
B1 Bit activating a periodical variation of reference voltage 2 0
B2 Bit activating automatic compensation of the offset in voltage acquisition channels 4 0/1 (1)
B3 Not used 8 0
B4 Bit enabling reading of 50/60 Hz jumper hardware 16 1
B5 Inversion APO(2) 32 1
B6 Three phase sensing active 64 0
B7 Voltage remote control by RAM location L[49] or input saturation ( in case of overflow ) 128 0
B8 Bit enabling reading of reference voltage by VOLT Trimmer 256 1
B9 Bit enabling reading of stability parameter by STAB Trimmer 512 1
B10 Bit enabling reading of underspeed protection threshold by Hz Trimmer 1024 1
B11 Bit enabling reading of excitation current threshold by AMP Trimmer 2048 1
B12 Bit enabling reading of external voltage input 4096 1
B13 Bit enabling DAC 8192 0
B14 60Hz active setting (jumper 60Hz closed and/or 60Hz active setting on configuration menu)(3) 16384 0/1 (1)
B15 Reserved 32768 0
TABLE 11 : BIT FUNCTION OF THE FOURTH STATUS WORD L[39] ( ACTIVE CONFIGURATION )
4. Volatile memory addresses
Add. Add name Range Access Description
32 VOLT Trimmer 0..32767 Read only VOLT Trimmer Position
33 STAB Trimmer 0..32767 Read only STAB Trimmer Position
34 Hz Trimmer 0..32767 Read only Hz Trimmer Position
35 AMP Trimmer 0..32767 Read only AMP Trimmer Position
36 First status word 0..3200 Read only Regulated voltage [tenths of volts]
37 Second status word 0..900 Read only Frequency [tenths of Hz]
38 Third status word 16bit Read only Active alarms
39 Fourth status word 16bit Read only Active configuration
40 Commands 16bit Write Reserved Word Commands – Do not use
41 Pext/Vext Inputs 0..32767 Read only Analogical input or external potentiometer value
42 Setpoint 0..32767 Read only Setpoint value
43 Setpoint 0..32767 Read only Value modified by regulator in case of alarms, soft-start, etc.
44 Measured Voltage 0..32767 Read only Internal variable
45 Estimated temperture 0..32767 Read only Estimates temperature of exciter windings
… … …
49 Reference corresponding to Vext 0..32767 Write Used if Vext input is disabled and voltage remote
control by RAM location is enabled (P[10]-Bit B7=1)
50 Peak to peak voltage 0..32767 Read only Internal variable
51 Three phase switch threeshold 0..32767 Read only Internal variable
52 Offset voltage 0..32767 Read only Internal variable (active only in single phase sensing)
56 Underexcitation observer 0..32767 Read only Observer of underexcitation or loss of excitation
(2)
TABLE 9 : VOLATILE MEMORY ADDRESSES
55 AMP protection threshold 0..32767 Read only Intervention threshold of overexcitation protection(1)
54 Ki/2P[12] 0..32767 Read only Integral gain not considering factor 2P[12] (1)
53 Kp/2P[11] 0..32767 Read only Proportional gain not considering factor 2P[11] (1)
5. Fourth Status Word (Location L[39])
Location L[39] indicates (almost in real time) the active configuration at any given time; it is not a simple
replication of the value recorded in parameter P[10], however, inasmuch as the bits B2, B6 and B14 adjust
their value only on the basis of the configuration set, but also of the effective operational status of the
DER1 at that time; for example, if the regulator is connected with three phase sensing, even if bit B6 of the
configuration word is set on 0 (automatic recognition of single phase – three phase activation), bit B6 of
location L[39] will have a value of 1; similarly, if the 60 Hz jumper is engaged and reading is enabled 8Bit
B4 of parameter P[10] set on 1), bit B14 of location L[39] will have a value of 1 even if the corresponding
bit B14 of the configuration word is set on 0.
The values of the fourth word of status (location L[39]) are shown in table 10, on the basis of the type of
the regulation and nominal frequency.

DER1 digital regulator instruction manual - rev. 05 - pag. 21
The parameter P[9] sets the excitation current limit: the value P[9]=0 is setting to zero the excitation
current, while the maximum value P[9]=32767 is removing the current limitation. The default value is P[9]
=32767. When the interval of action of the soft start has been exceeded, the output voltage moves to the
value set. The rapidity of the change is set by parameter P[18] (see paragraph on "Slow voltage
variations”)
1.2 Soft Start
In the event of fast start up of the prime mover or sudden regulator excitation with the generator running at
nominal speed an uncontrolled regulator could result in a temporary generator overvoltage or in a
transitory prime mover overload due to the high peak of excitation current..
These effects can be minimised by setting parameter “Delay” and “Excitation Limit” in the area “Soft-Start”
of the Settings/Advanced menu, corresponding to parameters P[8] and P[9] : during starting, they
determine a limit of the excitation current.
Parameter P[8] sets the duration of the excitation current limitation, namely the value of the parameter
corresponds to the number of periods in which the limitation is active. The default value is P[8]=0 which
corresponds to deactivation of the soft start. Considering that in most cases the alternator is already at
nominal speed, an estimate in temporal terms (corresponding to the setting “Delay” in Soft-Start area) for 4
pole machines, may be obtained with the formula:
SETTING OF VOLT, STAB, AMP and Hz PARAMETERS.
1. Voltage
1.1 Setting voltage.
Setting can take place through the trimmer or software: on sensing inputs 6/7 – 10/11/12 (with bridge 8-9),
15-16 and 20-21, the voltage can be set between 75÷150 Vac (scale H); on sensing inputs 4/5 -
9/10/11/12, 14-17 and 19-22 between 150÷300 Vac (scale F).
There are two ways to set from minimum to maximum value:
1. With the VOLT trimmer, which must be enabled by the Settings/potentiometers menu of DxR Termi-
nal software
2. With parameter P[19] (The Volt trimmer must be enabled from the Settings/Potentiometers menu:
the value 0 corresponds to minimum voltage, 16384 corresponds to the intermediate value
(respectively 112.5 V and 225 V), while 32767 corresponds to maximum voltage.
The setting is facilitated using the software DxR Terminal, through Settings/Potentiometers menu.
It is possible to vary voltage with respect to the value set, with the Pext input (terminals 29-30) if enabled
from the area Pext/Vext in the Settings/Advanced menu, with a 25Kohm or 100Kohm potentiometer, with
a range of variation that can be programmed up to ±100% (parameter P[16]. The default setting is ± 14%,
even if it is opportune not to exceed ±10%). Alternatively, variation can be made with continuous voltage
applied on Pext (terminal 30) or ±10V (terminal 32), based on the value of that voltage. If the Pext voltage
is disabled, it is possible to vary the voltage with parameter P[15] or location L[49]. For additional details
see the paragraph "Remote control of voltage".
Where fn= nominal frequency in Hz or n= nominal speed in R.P.M
nn
P
f
Pt

30
]8[
1
]8[
lim 
By way of example, for high power alternators of the ECO46 series, the following settings may be
experimented: Delay=1280ms (P[8]=64) and Excitation limit=50% (P[9]=16384); for low power alternators of
the ECP3 series, the effects of a reduction of both the duration and limitation of the current may be
experimented, such as Delay=320ms (P[8]=16) and Excitation limit=3,72% (P[9]=4096).
The optimal values of “Delay” and “Excitation limit” (parameters P[8] and P[9]) depend a great
deal on the type of alternator and final application and it must be found through experimentation.
An inappropriate setting of parameters P[8] and P[9] could cause failure of the alternator to
excite itself.