ABB SPACOM replaces REX615

From SPACOM to REX615: A Complete Technical Guide for Relay Modification

The lifecycle management of protective relays is a continuous challenge in the fields of power systems and industrial distribution. With the gradual discontinuation of the SPACOM series relays, many users are facing issues such as spare parts shortages, technical support, and termination of firmware updates. ABB's Relay Retrofit Program for SPACOM to REX615 provides a systematic solution to this dilemma. This article elaborates on how to use this renovation plan from an engineering practice perspective to smoothly replace the original SPACOM protection relay with the latest REX615 relay, covering the entire process of selection, mechanical installation, electrical wiring, configuration and debugging.

Why is it necessary to modify: End of Life for SPACOM Relays

The SPACOM series relays have been widely used in the protection, control, and monitoring of medium and low voltage distribution systems over the past few decades. Common models include sub series such as SPAA, SPAC, SPAD, SPAF, SPAJ, SPAM, SPAS, SPAU, etc. However, with the evolution of ABB's product line, these relays have entered a state of discontinuation. Continuing to use old relays will bring the following risks:

Difficult to obtain spare parts: unable to replace quickly after a malfunction, prolonging power outage time.

Insufficient communication capability: SPACOM relays often use traditional hard wired or serial protocols, making it difficult to integrate into the digital substation (IEC 61850) architecture.

Maintenance support terminated: firmware updates, fault diagnosis, and calibration services will no longer be provided.

Mechanical wear: After long-term operation, the reliability of the internal contacts, display screen, and power module of the relay decreases.

ABB's renovation plan aims to extend the overall lifespan of the switchgear by replacing it with REX615 relays, while providing full lifecycle service support. This solution not only restores the original protection function, but also adds new features such as status monitoring, advanced communication, and programmable logic as needed.

REX615: Technological advantages of replacing relays

REX615 belongs to the ABB Relion product family and is an integrated protection and control relay. Its design is compact and adopts a withdrawable unit structure, which is easy to maintain and test. Compared to SPACOM, REX615 has the following significant advantages:

2.1 Comprehensive communication protocol support

REX615 natively supports IEC 61850 (including Edition 1 and 2.1), IEC 60870-5-103, IEC 104, Modbus, and DNP3. This means that it can seamlessly integrate into modern substation automation systems, enabling GOOSE communication, SCADA remote control, and fault recording upload.

2.2 Higher protection performance

By using digital signal processors and algorithms, the protection action time is shorter and the accuracy is higher. Simultaneously supporting configurable protection function blocks, users can flexibly activate corresponding protection components according to application requirements (feeders, transformers, motors, etc.).

2.3 Enhanced Monitoring and Diagnosis

Built in circuit breaker wear monitoring, trip circuit monitoring, environmental temperature recording and other status monitoring functions provide data support for predictive maintenance.

2.4 Unified Engineering Tools

Using PCM600 (Protection and Control IED Manager) for configuration, setting values, and fault analysis, the same tool can manage the entire Relion series of relays, reducing training costs.

Compatible SPACOM models

The renovation plan currently supports SPACOM relay models covering a wide range of sub series. According to the document, the following models already have corresponding REX615 replacement plans (more models will be added in the future):

SPAA series: SPAA 120 C, SPAA 121 C, SPAA 341 C, SPAA 110 C, SPAA 115 C, SPAA 130 C, SPAA 131 C, SPAA 135 C, SPAA 140 C, SPAA 141 C, SPAA 142 C, SPAA 144 C, SPAA 160 C, SPAA 330 C, SPAA 331 C

SPAC series: SPAC 310 C, SPAC 312 C, SPAC 315 C, SPAC 317 C

SPAD Series: SPAD 346 C

SPAF series: SPAF 140 C

SPAJ series: SPAJ 110 C, SPAJ 111 C, SPAJ 115 C, SPAJ 131 C, SPAJ 135 C, SPAJ 140 C, SPAJ 141 C, SPAJ 142 C, SPAJ 144 C, SPAJ 160 C

SPAM Series: SPAM 150 C (NO/NC)

SPAS Series: SPAS 120 C

SPAU series: SPAU 110 C, SPAU 121 C, SPAU 130 C, SPAU 140 C, SPAU 330 C, SPAU 331 C

Before starting the renovation project, users should verify the complete model of the existing SPACOM relay and select the corresponding replacement kit in the ABB order code.

Content and selection of renovation kit

The deliverables provided by the renovation plan include not only the REX615 relay itself, but also a series of installation accessories and engineering services to ensure efficient and accurate on-site operations.

4.1 Standard Includes Items

REX615 relay: Pre configured (corresponding to the original SPACOM function) or empty configuration can be selected at the factory.

Modification connector kit: includes X100 (24 pin), X110 (24 pin), or X130 (18 pin) connectors, as well as a protective ground wire (2 meters long, 6mm ², with M4 ring terminals on both ends), X120 stickers, M3 × 8mm screws (T10).

Document: Wiring guidance provided for installation personnel.

Configuration Support Service: Configuration engineering support for REX615.

Cutting tool kit: a handheld cutter used to enlarge panel openings.

Installation bracket: Temporarily fix the connector for easy wiring.

Cover plate (only available when converting SPACOM 300 series to standard REX615).

4.2 Optional Ordering Items

Relion BIO Tester 610-611-615-620: Used for offline testing of REX615 relays.

Training: A one-day classroom training covering tool usage, modification processes, and pricing considerations.

4.3 Order Code Analysis

ABB provides two order codes for each SPACOM model:

Pre configured (suffix C): REX615 has been configured with logic and parameters according to the standard functions of the original SPACOM when it leaves the factory.

Without pre configuration (suffix N): REX615 is the default factory configuration, and users need to configure it themselves using PCM600.

For example, for SPAA 120 C, the order code is RRPSPAA120CREX615C (with pre configuration) or RRPSPAA120CREX615N (without pre configuration). Users should prioritize pre configured versions to save on-site debugging time.

In addition, the installation accessories have independent order codes:

Installation bracket (100 series): 1VFR100623E0001

Cutting tool kit (for SPACOM 100 and 300 series): 2RCA031784

Cutting head: 2RCA031786

Power supply unit: 2RCA032139

Battery charger: 2RCA032140

Backup battery: 2RCA031785

Cover plate (300 series): 1VFR100623A0001

Mechanical installation: modification of openings and use of brackets

The mechanical dimensions of SPACOM and REX615 are different. The former is mostly square panel openings, while REX615 has different widths and heights. Therefore, it is necessary to open and expand the doors or panels of the switchgear. The cutting tool kit provided by ABB is specifically designed for this purpose.

5.1 Instructions for using cutting tools

The cutting tool kit includes a battery powered power unit and a punching head (including punch and die). The operation steps are as follows:

Remove the existing SPACOM relay from the panel and retain the original opening.

According to the installation dimensions of REX615, align the mold of the cutting head with the original opening edge and determine the direction of the hole expansion (the most convenient direction can be chosen, such as expanding upwards or downwards).

Start the power unit, and the punching head completes a precise punching on the metal panel, capable of cutting up to 3.0mm thick steel plates.

The entire process does not require additional measurement or marking, nor does it require rust prevention treatment for the incision, as the punching process will not damage the surface coating.

This cutting method has the advantages of quietness, speed, no burrs, and precise size compared to traditional angle grinders or plasma cutting. ABB recommends replacing only the cutting head components during warranty claims, rather than the entire set of tools.

5.2 Temporary wiring assistance for installing brackets

After the mechanical opening is completed, installation brackets are required for actual wiring. The installation hole position of this bracket is consistent with the fixed hole position of the original SPACOM relay. Temporarily fix the bracket in its original position on the panel, and then plug the connector from the modified connector kit into the corresponding terminal of the bracket. In this way, construction personnel can remove the secondary wire from the original SPACOM terminal without carrying a relay and reconnect it according to the original terminal number marked on the connector. After the wiring is completed, remove the bracket. At this point, all secondary wires have been pre connected to the modified connector, and then plug the connector as a whole into the corresponding interface on the back of the REX615 relay.

5.3 Scenarios for the Use of Cover Plates

For SPACOM 300 series relays (such as SPAA 330 C), the panel opening size is larger than that of REX615 standard relays. At this point, a cover plate is needed to fill the excess gap. The cover plate order code is 1VFR100623A0001, installed between REX615 and the panel, providing a clean appearance and dust-proof seal.

Electrical Wiring: Exquisite Design for Transforming Connectors

The most time-saving part of the renovation plan is the modification of the connector kit. The connector (X100, X110, or X130) of this kit has the terminal number of the original SPACOM relay printed on the top. Users do not need to refer to the schematic diagram, they only need to remove the secondary wire inside the switchgear from the SPACOM terminal and connect it to the same numbered terminal on the connector.

6.1 Selection of connector types

Determine which connectors are needed based on the replaced SPACOM model. The document provides a detailed mapping table. For example:

SPAA 120 C: Requires X100 and X110 (i.e. two 24 pin connectors)

SPAA 341 C: Requires X100, X110, and X130 (two 24 pin and one 18 pin)

SPAM 150 C: Only X130 (normally open or normally closed version) is required

The connector is installed on the REX615 relay at the factory. But for the convenience of wiring, users can first unplug the connector from the relay and install it on the bracket for offline wiring.

6.2 CT/VT Wiring Special Handling

For the secondary wires of current transformers (CT) and voltage transformers (VT), independent push in terminals are provided in the modified connector kit due to the precision and polarity involved. During the bracket auxiliary wiring stage, the CT/VT wire is first connected to the push in terminal. When the connector is finally installed back into REX615, it is necessary to remove these CT/VT wires from the push in terminals and connect them to the corresponding positions of REX615's X120 terminals. This step is the only part that requires reference to the relay manual, but the amount of operation is very small.

6.3 Protection Grounding

The kit includes a 2-meter-long, 6mm ² yellow green grounding wire with M4 ring terminals at both ends. One end is fixed on the grounding stud of REX615, and the other end is connected to the grounding bar of the switchgear. Ensure reliable grounding of the relay to prevent electromagnetic interference and electric shock risks.

Engineering configuration: Mapping from SPACOM functionality to REX615

The renovation plan provides configuration support services. Users can request assistance from ABB engineers to complete the configuration when placing an order. The configuration work is based on ABB's PCM600 software and REX615's dedicated connectivity package.

7.1 Pre configuration plan

If a pre configured order (suffix C) is selected, ABB will configure REX615 according to the standard functionality of the original SPACOM relay. This includes:

The activation of protection functions (overcurrent, ground fault, phase to phase short circuit, etc.) corresponds to the set value range.

The mapping of binary input/output is consistent with the original SPACOM, ensuring that external circuits (such as trip coils, signal lights, pressure plates) do not need to be modified.

The logic of the alarm LED indicator is the same as that of the original relay.

After the pre configuration is completed, users only need to input specific setting values (such as overcurrent setting value, time constant) on site to put it into operation.

7.2 Custom Configuration Extension

Due to the fact that REX615 has more functions than SPACOM, users can use this renovation to add additional protection (such as negative sequence overcurrent, thermal overload, circuit breaker failure), measurement functions (harmonic analysis, power factor), or control logic (interlocking, automatic switching). These functions can be graphically configured through the Application Configuration tool of PCM600 and saved as templates for batch renovation projects.

7.3 Fixed value setting method

Fixed value parameters can be modified in the following two ways:

The local HMI: REX615 front panel comes with an LCD screen and buttons, suitable for small-scale on-site adjustments.

PCM600: Connect relays through Ethernet or serial port, upload setting value groups in batches, suitable for overall project debugging.

Implementation steps for on-site renovation (recommended process)

Based on the above technical preparations, it is recommended that the on-site team follow the following steps to carry out the renovation:

Power off isolation: Confirm that the switchgear has been powered off, the CT secondary side short circuit or open circuit protection is in place, and hang the grounding wire.

Record the original wiring: Take photos or mark each terminal wiring of the original SPACOM. Although the modified connectors have corresponding numbers, it is recommended to backup them.

Dismantling the old relay: Remove the panel fixing screws of SPACOM, unplug the back connector (if any), and take out the relay.

Installation bracket: Fix the installation bracket in the original relay position.

Wiring: Remove the secondary wire from the SPACOM terminal and reconnect it to the modified connector on the bracket according to the number on the connector. Connect the CT/VT wire to the push in terminal first.

Cutting hole: Use the cutting tool kit to enlarge the panel hole to the required size of REX615. If a cover plate is used, locate the hole according to the cover plate.

Remove bracket: After all wiring is completed, remove the pre connected modified connector from the bracket.

Install REX615: Insert the relay into the panel opening and secure it with screws. Then insert the modified connector into the back of REX615 (X100, X110, X130, etc.). Finally, connect the CT/VT wire from the push in terminal to the X120 terminal of REX615.

Grounding and inspection: Connect the grounding wire, check that all wiring is securely fastened and there are no omissions.

Power on and configuration: Close the DC power supply and perform relay self-test. If you choose pre configuration, enter the fixed value directly; If it is an empty configuration, download the configuration file through PCM600.

Functional testing: Use a relay protection tester to verify the protection action logic, trip outlet, and signal indication. Optional Relion BIO Tester for automated testing.

Resume operation: After confirming that there are no errors, remove the temporary grounding, restore the CT circuit, and put the switchgear into operation.

Common problems and troubleshooting suggestions

Based on actual renovation experience, the following issues are relatively common:

9.1 The cutting tool cannot cut the panel

Check if the battery is fully charged; Confirm that the panel thickness does not exceed 3.0mm; check if the punch and die are worn, and replace the cutting head (2RCA031786) if necessary.

9.2 Difficulty in plugging and unplugging modified connectors

Ensure that the connector is aligned with the corresponding interface on the back of the relay, and use the M3 × 8mm screws (T10) provided in the kit to secure the connector. Do not use strong force to avoid damaging the pins.

9.3 Some pre configured functions do not match the original SPACOM

Due to the special customization logic of certain SPACOM models, standard pre configurations may not fully match. At this point, ABB configuration support services should be contacted to provide the complete order and logic diagram of the original relay, and generate customized configurations.

9.4 Communication cannot be established

Check the IP address settings of REX615 (default values need to be consulted in the manual); Confirm the use of the correct communication protocol (GOOSE and MMS need to be configured for IEC 61850); For serial protocols, check if the pin definitions match the serial converter of PCM600.

9.5 Relay alarm "CT circuit disconnection"

Usually it is because the CT secondary wire becomes loose or the polarity is reversed during the rewiring process. Check if the CT wire on the X120 terminal is secure, and use a clamp gauge to measure if the CT circuit current is balanced.