 ABSTRACT: This white paper describes the proper hookup connections for common mode input style PMI power analyzers. PMI offers the ability to monitor with two styles of voltage input connections to provide the user with the most flexibility when troubleshooting power quality issues. The VIP, iVS-3, and iVS-3/600P have differential voltage inputs where the Eagle, Revolution, and Vision have common mode voltage inputs. Although the differential and common mode voltage inputs can monitor the same circuit types; the connections on the circuit differ slightly. In order to fully understand the circuit hookup diagram, some circuit theory will be reviewed. COMMON MODE OR SINGLE ENDED INPUTS Common mode inputs, as shown in Figure 1 below, only provide one input for each channel and share a "common" point between channels. Depending on the circuit type, the common point could either be neutral or floating. In the case of the WYE circuit, the common point is the neutral connection. All voltage measurements are referenced to neutral and considered to be phase to neutral measurements. In the case of the Delta circuit, the common point is floating. All measurements are referenced to the corresponding phase voltage and the DELTA voltages are calculated. DIFFERENTIAL VOLTAGE INPUTS Differential inputs (Figure 2) provide two inputs for each channel that respond to the signal difference between them. Differential inputs do not share a common point between the channels of the recorder. The voltage measurements in any circuit type are the difference between channel connections. Since differential input recorders do not share a "common" point, they could be used to monitor two circuits that are completely isolated. WHITE PAPER: COMMON MODE INPUT RECORDER - HOOKUP DIAGRAM WALKTHROUGH Amplifier + _ Output AC Input Common Common Amplifier + _ Output AC Input Set circuit type to "WYE." THREE PHASE WYE CH1, CT CH1, Black CH3, Blue CH2, CT CH3, CT CH2, Red A B C Common, White CH 4, Yellow Figure 1. Common mode input circuit diagram Figure 2. Differential input circuit diagram Figure 3. Three Phase WYE Tools you need. People you trust. NOTE: The "common" connection or white wire has no reference in the phase-to-phase measurements in a Open Delta system. The "common" is only used to power the recorder. FOUR WIRE DELTA There are 9 connections associated with the 4 Wire Delta System including the current channels. CH1 (A) voltage and current, CH2 (B) voltage and current, CH3 (C) voltage and current, and CH4 which is optional. Since the 4 Wire Delta System has a neutral connection, the white wire neutral connection on the recorder needs to be made at this point. As shown in Figure 6, the white wire is connected to the common point and is all that is required to make up this connection. The line connections are the remaining points that need to be connected in a 4 Wire Delta fashion. As shown in Figure 6, the CH1 or A phase connection is the black wire, the CH2 or B phase connection is the red wire, the CH3 or C phase connection is the blue wire, and the CH4 (optional channel) is the yellow wire. The current channels are connected respectively with the voltage channel connections as shown in Figure 6. In order to monitor with the 4 Wire Delta connected circuit type, the recorder must be initialized to 4 W ire Delta. TWO ELEMENT DELTA The Two Element Delta uses the same connection scheme and initialization as the 3 Wire Delta circuit. There are 8 connections associated with the Two Element Delta system including the current channels. CH1 (A) voltage and current, CH2 (B) voltage, CH3 (C) voltage and current, and CH4 which is optional. Since the Two Element Delta system has no neutral connection, the white wire neutral connection on the recorder needs to be made on the CH2 (B) phase channel. As shown in Figure 7, the white wire is connected to the CH2 (B) phase and is all that is required to make up this connection. The line connections are the remaining points that need to be connected in a Two Element Delta fashion. As shown in Figure 7, the CH1 or A phase connection is the black wire, the CH2 or B phase connection is the red wire, the CH3 or C phase connection is the blue wire, and the CH4 (optional channel) is the yellow wire. The current channels are connected respectively with the voltage channel connections as shown in Figure 7. In order to monitor with the Two Element Delta connected circuit type, the recorder must be initialized to 3 W ire Delta. the 3-Phase Delta connected circuit type, the recorder must be initialized to 3 W ire Delta. NOTE: The "common" connection or white wire has no reference in the phase to phase measurements in a 3-Phase Delta system. The "common" is only used to power the recorder. OPEN DELTA The Open Delta uses the same connection scheme and initialization as the 3 Wire Delta circuit. There are 9 connections associated with the Open Delta System including the current channels. CH1 (A) voltage and current, CH2 (B) voltage and current, CH3 (C) voltage and current, and CH4 which is optional. Since the Open Delta System has no neutral connection, the white wire neutral connection on the recorder needs to be made on the CH2 (B) phase channel. As shown in Figure 5, the white wire is connected to the CH2 (B) phase and is all that is required to make up this connection. The line connections are the remaining points that need to be connected in a Delta fashion. As shown in Figure 5, the CH1 or A phase connection is the black wire, the CH2 or B phase connection is the red wire, the CH3 or C phase connection is the blue wire, and the CH4 (optional channel) is the yellow wire. The current channels are connected respectively with the voltage channel connections as shown in Figure 5. In order to monitor with the Open Delta connected circuit type, the recorder must be initialized to 3 Wire Delta. WHITE PAPER: COMMON MODE INPUT RECORDER - HOOKUP DIAGRAM WALKTHROUGH Set circuit type to "wire delta." THREE PHASE DELTA CH1, CT CH1, Black CH3, Blue CH2, CT CH3, CT CH2, Red Common, White CH 4, Yellow: Optional, Connect to Any A B C OPEN DELTA CH1, CT CH1, Black CH3, Blue CH2, CT CH3, CT CH2, Red Common, White Set circuit type to "3 wire delta." CH 4, Yellow: Optional, Connect to Any A B C Set circuit type to "4 wire delta." FOUR WIRE DELTA A B C CH 4, Yellow CH1, CT CH1, Black CH3, Blue CH2, CT CH3, CT CH2, Red Common, White Figure 4. Three Phase Delta Figure 5. Open Delta Figure 6. Four Wire Delta Tools you need. People you trust. 102411 WP39 2 WIRE SINGLE PHASE There are 3 connections associated with the 2 Wire Single Phase System including the current channel. CH1 voltage and current, and all the other channels are optional. Since the 2 Wire Single Phase System has no neutral connection, the white wire connection on the recorder needs to be made at the corresponding phase measurement. As shown in Figure 9, the white wire is connected to the common point and is all that is required to make up this connection. The line connections are the remaining points that need to be connected in a 2 Wire Single Phase fashion. As shown in Figure 9, the CH1 connection is the black wire and is all that is required to make up the line connection. The CH1 current is connected respectively with the voltage channel connection as shown in Figure 9. In order to monitor with the 2 Wire Single Phase connected circuit type, the recorder must be initialized to WYE. 3 WIRE SINGLE PHASE There are 5 connections associated with the 3 Wire Single Phase System including the current channels. CH1 voltage and current, CH2 voltage and current and all other channels are optional. Since the 3 Wire Single Phase System has a neutral connection, the white wire neutral connection on the recorder needs to be made at this point. As shown in Figure 10, the white wire is connected to the common point and is all that is required to make up this connection. The line connections are the remaining points that need to be connected in a 3 Wire Single Phase fashion. As shown in Figure 10, the CH1 connection is the black wire, the CH2 connection is the red wire. The current channels are connected respectively with the Voltage channel connections as shown in Figure 10. In order to monitor with the 3 Wire Single Phase circuit type, the recorder must be initialized to WYE. NOTE: The "common" connection or white wire has no reference in the phase-to-phase measurements in a Two Element Delta system. The "common" is only used to power the recorder. 2 ½ ELEMENT WYE There are 8 connections associated with the 21/2 Element WYE system including the current channels. CH1 (A) voltage and current, CH2 Current, CH3 (C) voltage and current, and CH4 which is optional. Since the 21/2 E lement W YE s ystem h as a neutral connection, t he white wire neutral connection on the recorder needs to be made at this point. As shown in Figure 8, the white wire is connected to the common point and is all that is required to make up this connection. The line connections are the remaining points that need to be connected in a 21/2 Element WYE fashion. As shown in Figure 8, the CH1 or A phase connection is the black wire, the CH3 or C phase connection is the blue wire and the CH4 (optional channel) is the yellow wire. NOTE: The CH2 (B) voltage is not connected in the 21/2 Element WYE system. The current channels are connected respectively with the voltage channel connections as shown in Figure 8. In order to monitor with the 21/2 Element WYE connected circuit type, the recorder must be initialized to 21/2 Element WYE. WHITE PAPER: COMMON MODE INPUT RECORDER - HOOKUP DIAGRAM WALKTHROUGH Set circuit type to "2.5 el. wye." 2 1/2 ELEMENT WYE Common, White CH1, CT CH1, Black CH3, Blue Voltage CH2 CH2, CT CH3, CT is unused N B C CH 4, Yellow Set circuit type to "wye" TWO WIRE SINGLE PHASE CH1, CT CH1, Black All other channels are optional. Common, White THREE WIRE SINGLE PHASE CH1, CT N CH2, CT CH1, Black CH2, Red Set circuit type to "wye" All other channels are optional. Common, White Figure 8. 2 1/2 Element WYE Figure 9. 2 Wire Single Phase Figure 10. 3 Wire Single Phase Set circuit type to "3 wire delta." TWO ELEMENT DELTA CH1, CT CH1, Black CH3, Blue CH3, CT CH2, Red Common, White CH 4, Yellow: Optional, Connect to Any PTS on A-B and B-C CTS on A and C A B C Figure 7. Two Element Delta Tools you need. People you trust. 102411 WP39 WHITE PAPER: COMMON MODE INPUT RECORDER - HOOKUP DIAGRAM WALKTHROUGH SETTING THE CIRCUIT TYPE In order for the calculations to be correct when monitoring a s pecific circuit, the recorder must be initialized to monitor that circuit type. The circuit type is set on the Basic Initialization Screen as shown in Figure 11. CONCLUSION PMI offers the ability to monitor any circuit type found in the industry. With a little background knowledge in the circuit types that are commonly used in power quality monitoring scenarios, connecting your recorder will be easier and more reliable. The time spent reviewing the connection diagrams will be well worth the effort when investigating a p ower quality issue. For a PDF of the recorder hookup diagrams visit the PMI website at http://www.powermonitors.com< |