Thiết bị kiểm tra relay HTI DVS3 mk2

Features

· 3-f Voltage output from 1-f supply

· 0-133V f-N output voltage 

0-266V/292V f-N with optional VT box

· 45VA/phase maximum output

· Variable Frequency 40-999.9Hz

· Phase shift ±180.0°

· Multi-function timing system

· Ideally suited to testing G59 schemes

· Step change of phase and df/dt

· Large back-lit liquid crystal display

· Compact and lightweight

· Automatic mains voltage selection

The  DVS3  mk2  is  ideally  suited  to  testing  G59  protection,

including  loss  of  mains  protection.    Vector  surge  and  df/dt

(ROCOF)  relays  may  be  simply  tested  and  timed,  as  can

other protection requiring one to three voltages, including:

· Under and over frequency relays

· Under and over voltage relays

· Synchronising relays

· df/dt & ROCOF relays

· Vector surge relays

· Transducers

In  conjuction with  a  current  source  (such  as  the  200ADM),

the  DVS3  mk2  can  be  used  to  test  protection  requiring

current injection with a phase-shiftable voltage including:

· Directional relays

· Distance protection

The display on the DVS3 is back-lit and exceptionally

clear.  Menu options on the left are selected by dedicated

buttons on the panel next to the display, allowing

immediate access to adjust voltage, phase and frequency. 

Phase to phase and phase to neutral voltages are both

shown on the display, along with frequency and phase

Optional 260V

VT box

· Power transducers DVS3 mk2 Specification

Output

The  output  of  the  DVS3 mk2  has  four  4mm  safety  sockets  for

phases A, B, and C and neutral.  The neutral connection may be

omitted for a delta connection.

Voltage                                     0-133Vac phase-neutral

                                                    0-230Vac phase-phase

Current (continuous)                  200mA at 133V, 120mA at 0.1V*

Current (5min on/ 15min off)    335mA at 133V, 200mA at 0.1V*

Voltage resolution                    0.1V phase-neutral

Phase rotation                          ±180º

Voltage accuracy                     ±0.3%rdg+3d

*The current trip drops linearly between maximum and minimum output voltage. All

output ratings are based on an ambient temperature of 25°C.

Timing System

The timing system on the DVS3 mk2 is flexible and  transparent

in operation.  Step changes of any quantity may be generated by

typing  in  value using  the keypad.   Entering a  value  in  this way

automatically  resets  and  starts  the  timer  when  the  change  is

applied.   The  timer  then  stops  on  a  change  of  state  of  either

contact input.  More complex timing functions are handled by the

PF-F-PF mode.

Two contact inputs are provided, both of which have LEDs and a

mimic  on  the  display  to  show  the  contact    state.   The  contact

inputs auto-select for normally open or normally closed contacts. 

A DC voltage can also be used to trigger the timer using the Vdc

contact.

Timer resolution                       1ms

Timer full scale                         999.999s

Timer accuracy                        ±0.01%rdg+2d

Contact O/C voltage               24V

Contact S/C current                 20mA

Vdc input range                        24-240Vdc

Protection and Safety

The  DVS3  mk2  is  CE  marked  and  is  designed  to  meet  the

requirements  of  BS  EN61010.   The  outputs  are protected  by

overcurrent  and  thermal  trips,  and  the  contact  inputs  are

protected by  PTC  thermistors.  The phase  lock current  input  is

fuse  protected,  and  the  voltage  input  is  impedance  protected. 

An earth terminal is provided for connection to a local earth.

Supply Requirements

115V/230V±10%±10% auto-selecting, 45-65Hz 1ph 425VA max

Temperature Range

Storage -20°C to 60°C           Operating 0°C to 45°C

Lead Set Specifications

1 x 3m 4 core output lead terminated in 4mm plugs

1 x 3m 2 core timer lead terminated in 4mm plugs

Dimensions                                   Weight

380mm x 314mm x 221mm               9.1kg

Accessories

Output  lead  set,  lead  set  case,  mains  lead,  spare  fuse set,

operating manual.

Optional Accessories

Printer, 133:266V step up VT box, 133:292V step up VT box.

Modes of Operation

Variable Frequency Mode

This mode  allows  full  control  of  frequency,  voltage  and  phase. 

The  voltage  and  phase may  be  controlled  individually  for  each

phase  or  for  all  three  phases  together.   All  parameters  are

continuously variable using the adjust control, and step changes

of any value may be generated by  typing  the  required value on

the  keypad.    The  new  value is  applied  to  the  output when  the

enter key  is pressed.   The  timer automatically  resets and starts

when  a  step  change  of  value  is  entered,  and  stops  if  either

contact  input changes state.   Step changes of phase  for  testing

Vector Surge relays are easily generated in this mode.

Frequency resolution          0.01Hz  40.00-99.99Hz

                                             0.1Hz     100.0-999.9Hz

Frequency accuracy           ±0.01%rdg+1d

Phase resolution                  0.1º

Phase accuracy                ±0.3º phase to phase

Phase Lock Mode

The  frequency  and  phase  of  the  output  are  controlled  by  an

external  reference  in phase  lock mode.  The  reference may  be

the mains  supply  to  the DVS3 mk2,  an external  voltage,  or  an

external  current.   This  mode  allows  testing  of  directional  and

distance  protection  in  conjunction  with  an  external  current

source.

Phase lock range               45-65Hz

External voltage ref.           20-250V AC

External current ref.            0.2-5A AC

Phase resolution                  0.1º

Phase accuracy                ±0.3º phase to phase

                                           ±3.0º reference to output

df/dt and ROCOF (Rate Of Change Of Frequency)

Loss  of mains  protection  often  takes  the  form  of  a  df/dt  relay,

sensitive  to  the  rate  of  change  of  frequency  over  time.   The

DVS3 MK2  is  able  to  generate  a  swept  frequency  output with

accurate  rates  of  change  of  frequency  between  preset

frequencies.   The  rate of change may be continuously varied  to

find  the  relay  setting  or  stepped  to  time  the  relay.    The  output

may  be  set  to  either  sweep  continuously  or  generate  single

sweeps with timing.

Frequency range                      45.00-65.00Hz

Default sweep range              49.75-50.25Hz (50Hz supply)

                                                   59.75-60.25Hz (60Hz supply)

Rate of change range           0.010-3.000Hz/s

Pre-fault - Fault - Post-fault Mode

PF-F-PF mode  allows  extra  flexibility  in  testing where  complex

events must be  timed or several sets of values must be applied

to a relay in turn.  This mode allows three sets of values to be set

in  advance  (pre-fault,  fault,  and  post-fault  values).   The  DVS3

MK2 may be set to switch from one state to the next on a change

of contact or after a specific time.   In addition,  the timer may be

set to start or stop on any one of the state changes of a change

of contact state.  This mode allows frequency, phase and voltage

to be changed simultaneously if required.