Monitoring Relays 3-Phase Load Guard Types DWB0, PWB0 DWB0 PWB0 TRMS load guard relays for three phase balanced applications Measuring if the power factor is within set limits Measure voltage on own power supply Measuring ranges: A, 0A, MI current transformers delay to 30 s knob adjustable Separately adjustable upper/lower level on absolute scale Programmable latching or inhibit at set level Automatic and manual start and stop of the system Output: A SPDT relay.d. or.e. selectable For mounting on DI-rail in accordance with DI/E 0 0 (DWB0) or plug-in module (PWB0) 4 mm Euronorm housing (DWB0) or 36 mm plug-in module (PWB0) LED indication for relay, alarm and power supply Product Description DWB0 and PWB0 are precise TRMS power factor monitoring relays for 3- phase balanced systems. They can be used for monitoring the actual load of asynchronous motors and other symmetrical loads, where the power factor is almost proportional to the load. The relay measures the power factor (cos ϕ), that is the ratio between the active and the apparent power of a motor. Start/stop input allows to use a manual switch to start and stop the motor, without the need of an auxiliary device. The advantage of using the latch function is that the relay can be kept energized even after the end of the alarm condition. Inhibit function can be used to avoid relay operation when not desired (maintenance, transients). The LED's indicate the state of the alarm and the output relay. Ordering key Housing Function Type Item number Output Supply Range DWB 0 C M4 0A Type Selection Mounting Output Supply: Supply: Supply: Supply: 0 to 40 VAC 30 to 4 VAC 30 to 40 VAC 600 to 60 VAC DI-rail SPDT DWB 0 C M3 0A DWB 0 C M4 0A DWB0 C M6 0A Plug-in SPDT PWB 0 C M3 0A PWB 0 C M4 0A Input Specifications Input Voltage (Own power supply): 3 - phase DWB0:,, PWB0:, 6, 7 M3: 0 to 40 VAC ± % DWB0CM4: 30 to 40 VAC ± % PWB0C : 30 to 4 VAC ± % DWB0CM6: 600 to 60 VAC ± % - phase DWB0CM3:, (connect pins, ) PWB0CM3:, 6 (connect pins 6, 7) 0 to 40 VAC ± % Current: DWB0: A, 0A:, I MI...:, PWB0: A, 0A:, 0 MI...:, Measuring ranges Upper level Lower level factor (cos ϕ) 0. to 0. 0. to 0. AACrms Max. curr. (30 s) Direct input: 0. to A 30A to 0A 0A Standard CT (examples) TADK 0 A/ A to 0 A 60 A TAD 0 A/ A to 0 A 0 A TAD6 400 A/ A 40 to 400 A 40 A TAD 000 A/ A 00 to 000 A 00 A TACO00 6000 A/ A 600 to 6000 A 700 A MI CT ranges MI 00 0 to 00 A 3 AAC MI 00 0 to 00 A 000 AAC Specifications are subject to change without notice (3.0.07) Gross Automation (77) 6-3700 www.carlogavazzisales.com sales@grossautomation.com
DWB0, PWB0 Input Specifications (cont.) ote: The input voltage cannot raise over 300 VAC with respect to ground (PWB0 only) input DWB0 Terminals Z, PWB0 Terminals, Disabled > 0 kω Enabled < 00 Ω Pulse width > 00 ms Hysteresis PF approx 0. Output Specifications Output SPDT relay Rated insulation voltage 0 VAC ratings (AgSnO ) µ Resistive loads AC A @ 0 VAC DC A @ 4 VDC Small inductive loads AC. A @ 0 VAC DC 3. A @ 4 VDC Mechanical life 30 x 0 6 operations Electrical life 0 operations (at A, 0 V, cos ϕ = ) Operating frequency 700 operations/h Dielectric strength According to E 6047- Dielectric voltage kvac (RMS) Rated impulse withstand volt. 4 kv (./0 µs) General Specifications delay to 30 s ± 0. s Reaction time (input signal variation from -0% to +0% or from +0% to -0% of set value) Alarm delay < 00 ms Alarm OFF delay < 00 ms Accuracy ( min warm-up time) Temperature drift ± 000 ppm/ C Delay alarm ± 0% on set value ± 0 ms Repeatability ± 0.% on full-scale Indication for supply LED, green Alarm LED, red (flashing Hz during delay time) Output relay LED, yellow Environment Degree of protection IP 0 Pollution degree 3 (DWB0), (PWB0) Operating temperature @ Max. voltage, 0 Hz -0 to 60 C, R.H. < % @ Max. voltage, 60 Hz -0 to 0 C, R.H. < % Storage temperature -30 to 0 C, R.H. < % Housing Dimensions DWB0 4 x 0 x. mm PWB0 36 x 0 x 4 mm Weight Approx. 0 g Screw terminals Tightening torque Max. 0. m acc. to IEC 6047 UL, CSA Yes Approvals CE-Marking EMC Electromagnetic Compatibility Immunity According to E 6000-6- Emissions According to E 6000-6-3 Supply Specifications supply Overvoltage cat. III Rated operational voltage (IEC 60664, IEC 6003) Through terminals: DWB0:,, PWB0:, 6, 7 M3 77 to 76 VAC 4 to 6 Hz DWB0CM4 33 to VAC4 to 6 Hz PWB0CM4 33 to 477 VAC 4 to 6 Hz DWB0CM6 0 to 73 VAC 4 to 6 Hz Dielectric voltage one Dielectric voltage supply to output 4 kv Rated operational power M3: VA @ 30 VAC, 0 Hz M4: 3 VA @ 400 VAC, 0 Hz M6: VA @ 600 VAC, 0 Hz Supplied by and Mode of Operation DWB0 and PWB0 can be used for monitoring the actual load of asynchronous motors. The relay measures the absolute value for the power factor of the system PF= Active /Apparent that is for balanced system with sinus waveforms the cosine of the angle between motor current and motor voltage (cos ϕ). As cos ϕ varies with the load of the motor, underload and overload can be indirectly detected by DWB0 and PWB0. The relation between the load and cos ϕ depends on the type of motor. As a guideline to ensure correct working conditions for a motor, the upper level could be set above the cos ϕ marking on the motor, and the lower level under this value. It is anyway recommended to make the adjustment in connection with a practical test. The relay has an adjustable power delay in order to avoid overload detection during motor start. Example Latching mode, relay E In this application DWB0 or PWB0 are connected to an external current metering transformer, type MI..., (connected between & ) as Specifications are subject to change without notice (3.0.07) Gross Automation (77) 6-3700 www.carlogavazzisales.com sales@grossautomation.com
DWB0, PWB0 Mode of Operation (cont.) well as to a 3-phase asynchronous motor. The relay energizes as soon as the power supply is applied. After the power delay, the unit starts measuring cos ϕ. If cos ϕ is within the setpoints the relay is energized. As soon as the power factor drops below the lower setpoint or exceeds the upper setpoint the output relay releases and the red LED turns on after the set time has expired. To restart the cos ϕ measurement, connect Z and ( and ) or interrupt the power supply for at least s. Example on-latching mode, relay E DWB0 and PWB0 react as described in the previous example except for the automatic reactivation of the relay as soon as cos ϕ is back within the two setpoints. When the measured cos ϕ exceeds the set upper level, the red LED starts flashing. The output relay releases after the set time period. When the measured cos ϕ drops below the set lower level, the red LED starts flashing, and the output relay releases after the set time period. When the output relay releases there will be no LED indication. Example 3 -Phase load monitoring DWB0CM30A and PWB0CM30A can be used for monitoring the power factor of a -Phase load with 0 to 40 V AC mains voltage. In this case the power supply has to be connected between, (or, 6), and (or 6 and 7) have to be connected. Example 4 Start/stop mode, relay E In this application DWB0 or PWB0 are directly connected to a 3-phase asynchronous motor. The relay energizes as soon as the power supply is applied and the start/stop contact is closed. After the power delay, the unit starts measuring cos ϕ. If cos ϕ is within the setpoints the relay energizes. As soon as the power factor drops below the lower setpoint or exceeds the upper setpoint the output relay releases and the red LED turns after the set time has expired. When the start/stop contact is opened the relay de-energizes immediately. To restart the system just connect the start/stop contact. ote : to use the start/stop function the output relay has to command a contactor connected in series to the load (see last two wiring diagrams). ote : in case of current below the minimum level the alarm is conventionally. ote 3: (3-phase voltage): connect the 3-phase power supply to the terminals, and (DWB0) -, 6 and 7 (PWB0) taking care of the sequence. Function/Range/Level/Time Setting Select the desired function setting the DIP-switches to 4 as shown on the right. To access the DIP-switches open the plastic cover using a screwdriver as shown on the right. If DIP switch 3 is set to (start/stop) the position of DIP-switch 4 does not affect the products working mode. Centre knobs: Setting of upper and lower level of cos ϕ 0. to 0.. Lower left knob: Setting of delay on absolute scale: 0. to 30 s. Lower right knob: Setting of power delay on absolute scale: to 30 s. Input current range (terminals, I or 0, ) : 0A OFF: A/MI input Relay status : Relay de-energized in normal condition OFF: Relay energized in normal condition Working mode : input for start/stop functions OFF: input for latch/inhibit functions input (SW4 does not affect the working mode if SW3 is ) : Latch function enable OFF: Inhibit function enable DWB0 PWB0 input Z I input 0 6 otes.dip-switch 3 set enables the start/stop function that is managed by the closingopening of the contact input..dip-switch 3 set OFF enables the input contact for the latch/inhibit functions: the selection between these is allows by the DIP switch 4. The following table shows how the input contact manages the mode of operation: input working mode CLOSED OPE LATCH OT ACTIVE ACTIVE IHIBIT ACTIVE OT ACTIVE START/STOP START STOP Specifications are subject to change without notice (3.0.07) 3 Gross Automation (77) 6-3700 www.carlogavazzisales.com sales@grossautomation.com
DWB0, PWB0 Operation Diagrams Latch function - E relay supply Latch contact (Closed = latch not active) Upper Level Lower Level Relay T T T Inhibit function - D relay supply Inhibit contact (Closed = inhibit active) Upper Level Lower Level Relay Start and stop function - E relay supply Start/Stop contact (Closed = Start; Open = Stop) Upper Level Lower Level Relay T T Wiring Diagrams DWB0 - Direct connection PWB0 - Direct connection Z I 6 0 4 Specifications are subject to change without notice (3.0.07) Gross Automation (77) 6-3700 www.carlogavazzisales.com sales@grossautomation.com
DWB0, PWB0 Wiring Diagrams (cont.) DWB0 - Standard CT PWB0 - Standard CT Z I 6 0 DWB0 - MI CT PWB0 - MI CT Grey Z I 6 Grey 0 DWB0CM30A - Direct connection - -Phase Load L PWB0CM30A - Direct connection - -Phase Load L Z I 6 0 With the start/stop function enabled, it s necessary to use the following wiring diagrams (which are two examples among many others). It is possible for both 3-phase loads and -phase loads, either through direct connection or external current metering transformer. DWB0 - Direct connection - Manual start and stop (E relay) PWB0 - Direct connection - Manual start and stop (E relay) Start/stop Start/stop Z I 6 0 Specifications are subject to change without notice (3.0.07) Gross Automation (77) 6-3700 www.carlogavazzisales.com sales@grossautomation.com
DWB0, PWB0 Dimensions DI-rail Plug-in 4. 36 4 0 0 3. 63 0 63.. 6 Specifications are subject to change without notice (3.0.07) Gross Automation (77) 6-3700 www.carlogavazzisales.com sales@grossautomation.com