2615B CT Shorting Using ME Series Test Disconnect

7/23/2019 2615B CT Shorting Using ME Series Test Disconnect

1/5

PHOENIX CONTACT - 3/2015

UTME APPLICATION

CLIPLINE

Application Note

2615B

During testing or troubleshooting procedures, a currenttransformer (CT) cannot have its circuit interrupted whilecurrent flows through it. However, the CT needs the circuitbroken to test the transducer or inject a calibration signal.

The ME series of test disconnect terminal blocks andSB-ME switching bridge are designed to short the CT anddisconnect all power leading to the transducer or measure-ment devices.

There are three basic configurations of UTME blocks thatcan be used to accomplish this task: feed-through onlyblocks, a combination of the feed-through and knife-discon-nect blocks, and knife-disconnect blocks only. In 3-phasesystems, these configurations can be combined in differentdesigns (see Figures 5 and 7).

The first configuration is the most basic, using two MEDfeed-through terminal blocks and one SB-ME 2-8 switchingbridge.

1 2

ClosedOpenOutput

Input

s1 s2

s1 s2

O N O F F

L1 L2 L3

F1

F2

F3

F4

1 2 3

4 5 67 8 9

0

Simple, 3-phase

transducer test set

Figure 1. Two MED feed-through terminal blocks (configuration 1)

Configurations using two MED feed-through terminal blocksrequire at least one of the wires to the measurement deviceto be disconnected to inject the test/calibration signal. Thewires should only be removed after the outputs of the CThave been shorted. This is not an effective use of the MEseries of terminal blocks.

A second configuration uses one MED feed-through termi-nal block, one ME knife-disconnect terminal block, and one

SB-ME 2-8 switching bridge. This configuration can be with(Figure 3) or without (Figure 2) a ground block.

5 6

s1 s2

s1 s2

O N O F F

L1 L2 L3

F1

F2

F3

F4

1 2 3

4 5 6

7 8 9

0

ClosedOpenOutput

Input

Figure 2. One MED feed-through, one ME knife-disconnect andone switching bridge (configuration 2).

CAUTION

The SB-ME switching bridge must be installedin the bridging channel on the CT (or input) sideof the terminal block.

CT Shorting using ME Series Test Disconnect

Terminal Blocks


2/5

UTME Application

2 PHOENIX CONTACT 2615B

5 6 7

s1 s2PE

s1 s2 PE

O N O F F

L1 L2 L3

F1

F2

F3

F4

1 2 3

4 5 6

7 8 9

0

ClosedOpenOutput

Input

Figure 3. One MED feed-through and one ME knife-disconnectand one switching bridge connected to ground

The third configuration uses two ME knife-disconnect termi-nal blocks and one SB-ME 2-8 switching bridge (Figure 4).CT leads are connected to the input side of the ME seriesterminal block, and the transducer/measurement device isconnected to the output side.

5 6 7

s1 s2PE

s1 s2 PE

O N O F F

L1 L2 L3

F1

F2

F3

F4

1 2 3

4 5 6

7 8 9

0

ClosedOpenOutput

Input

Figure 4. Two ME knife-disconnects and one switching bridgeconnected to ground (configuration 3)

The knife disconnects should only be opened after theoutputs of the CT have been shorted.

If a ground reference or grounding of the CT output isrequired, an MED-PE terminal block can be substituted for

one of the MED feed-through terminal blocks or an MED-PEand FBS bridge can be added to any of the basic configu-rations. The FBS push-in bridge is then used to distributeground to one of the feed-through or knife-disconnectterminal blocks.

5 63 41 2

s1 s2s1 s2s1 s2

s1 s2s1 s2s1 s2

O N O F F

L1 L2 L3

F1

F2

F3

F4

1 2 3

4 5 6

7 8 9

0

B

(Closed)

A

(Open)Output

Input

Figure 5. Stacked design

The calibration/disconnect process using the design shownin Figure 5 is accomplished using the following steps.

1. Loosen the screws on the SB-ME 2-8 and move theshorting bar from position A to B to short the outputs ofthe CT.

Closed

(shunt up)

Open

(shunt down)

Figure 6. SB-ME switching bridge


3/5

UTME Application


2. Secure the shorting bar by tightening the screws. TheCT is now neutralized and the circuit is safe to open.

a. For circuits that include an ME knife-disconnectterminal block, the knife disconnects can now besafely opened.

b. For circuits using MED feed-through terminal blocks,

the wire(s) can now be disconnected.3. The test signal can now be injected into the transducer/

meter side of the circuit by inserting the signal probesinto the test adapters or connecting the signal to thedisconnected wiring of the measurement circuit.

To return the unit to normal operation, perform the abovesteps in reverse order:

1. Disconnect the test signal/probes from the transducerwires or remove probes from the test plugs.

a. For circuits that include the ME, the knife disconnectmust now be CLOSED.

b. For circuits that include the MED feed-through termi-

nal blocks, the wiring must now be reconnected.2. Open the switching bridge and return to normal

operation.

3. Loosen the screws and move the shorting bar fromposition B to A and snap into place.

4. Tighten the screws to prevent movement and inadver-tent shorting of the CT.

The CT measurement circuit is now functional.

1 2 3 4 5 6

s1 s2 s1 s2 s1 s2

s1 s2 s1 s2 s1 s2

O N O F F

L1 L2 L3

F1

F2

F3

F4

1 2 3

4 5 6

7 8 9

0

B

(Closed)

A

(Open)

Linked 3-phase

transducer test set

Output

Input

Figure 7. Linked design

Upon selection of the basic configuration, the final design ofthe ME test disconnect solution can accommodate variouslayouts. For example, Figure 7 shows both feed-throughand knife-disconnect terminal blocks, grouped by typeand bridged together. The CT leads are not paired witheach other. Use the following steps for CT shorting andcalibration.

1. Loosen the screws on the SB-ME 4-8 and move theshorting bar from position A to B to short all of the CToutputs at one time.

2. Secure the shorting bar by tightening the screws. AllCTs are now neutralized and the circuits are safe toopen.

3. Open the ME knife-disconnect terminal blocksswitches.

4. The test signal can now be injected into the transducer/meter side of the circuit by inserting the signal probesinto the test adapters of each measurement circuit.

To return the unit to normal operation, perform the above

steps in reverse order:

1. Remove the test/calibration signal probes from the testplugs.

2. Close the knife disconnects.

3. Open the switching bridge and return to normaloperation.

4. Loosen the screws and move the shorting bar fromposition B to A and snap into place.

5. Tighten the screws to prevent movement and inadver-tent shorting of CT.

The CT measurement circuit is now functional.


4/5

UTME Application


1

2

2

3

4

5

6

2

7

8

Figure 8. Components

Table 1 Ordering Data

Description Type Order No. Pcs./Pkt.

Terminal block, knife disconnect, screw connection UTME 6 3047400 1

Terminal block, feed-through, screw connection UTMED 6 3047413 1

Terminal block, ground block, screw connection UTMED 6-PE 3047442 1


5/5

UTME Application

2615B PHOENIX CONTACT GmbH & Co KG 32823 Blomberg Germany Phone: +49-(0) 5235-3-00 5PHOENIX CONTACT P.O. Box 4100 Harrisburg, PA 17111-0100 USA Phone: +1-717-944-1300www.phoenixcontact.com

Table 2 Accessories

Item Description Type Code Part No.

1 Test adapter, blueTest adapter, redTest adapter, yellowTest adapter, green

Test adapter, violetTest adapter, blackTest adapter, brownTest adapter, grayTest adapter, orange

PAI-4-FIX BUPAI-4-FIX RDPAI-4-FIX YEPAI-4-FIX GN

PAI-4-FIX VTPAI-4-FIX BKPAI-4-FIX BNPAI-4-FIX GYPAI-4-FIX OG

3032729303273230327453032758

30327613032774303278730327903034455

2 Zack marker strip, 10 sections ZB 8 1052002

3 Connecting bridge C-ME 6/2 3034442

4 Switch lock S-ME 6 3034439

5 Plug-in bridge, 2-positionPlug-in bridge, 3-positionPlug-in bridge, 4-positionPlug-in bridge, 5-positionPlug-in bridge, 6-positionPlug-in bridge, 10-position

FBS 2-8FBS 3-8FBS 4-8FBS 5-8FBS 6-8FBS 10-8

303028430302973030307303031030324703030323

6 Switching bridge, 2-positionSwitching bridge, 4-position

SB-ME 2-8SB-ME 4-8

30344683034484

7 End bracket E/NS 35 N 0800886

8 Terminal block cover D-UTME 6 3047426

Documents

2615B CT Shorting Using ME Series Test Disconnect