Indoor Instrument Transformers

Used for measurement in protection, control, and monitoring systems providing precise and reliable performance in medium voltage applications.

Protecting an evolving Indoor grid

ABB’s medium voltage indoor instrument transformers portfolio is highly versatile, offering a wide range of dimensions, designs, and ratings that can be tailored to meet customers' precise specifications, ensuring the perfect fit for their installations. Our portfolio, for IEC and other standards, is ideal for various medium voltage indoor applications, where air or gas-insulated medium voltage switchgear are the main installations, but also for compact secondary substations, motors and generators, dry-type transformers, and capacitor banks. As part of our portfolio, ABB offers the following product lines:

Indoor current transformers, up to 40.5 kV for metering, protection or zero-measurement purposes. The available designs include block type, bus type, and cable type current transformers.
Indoor voltage transformers, up to 40.5 kV for metering, protection or external power supply. The main designs are single-pole and double-pole voltage transformers. Single-pole transformers can be equipped with or without a fuse.

ABB medium voltage indoor instrument transformers are available for original equipment manufacturers (OEMs), panel builders and non-panel builders’ applications, Engineering, Procurement and Construction (EPC) partners, as well as end-users to incorporate them in their installations or retrofit and upgrade projects.

ABB supports customers and partners in staying ahead of increasing electrification needs, technology advancements, and regulatory changes, providing the power to adapt to a rapidly evolving energy landscape.

Indoor ITs portfolio

Current transformers

Current transformers
Cable CTs
0-current CTs
Voltage transformers
Metal coated VTs

Product scope

	TPU	KOKS	KOKM	KOKM for PGIS	KOKM for RMU	BD 00	KOKM	KOLMA/KOLA
Max.rated voltage	TPU 4 12 kV TPU 5 17.5 kV TPU 6 27.5 kV TPU 7 40.5 kV	KOKS 12 12 kV KOKS 17.5 17.5 kV	KOKM 1 1.2 kV	KOKM 072 0.72 kV KOKM 1 1.2 kV	KOKM 0.72 kV	BD 00 0.72 kV	KOKM 06 0.72 kV	KOLMA 0.72 kV KOLA 0.72 kV
Max.rated primary current	3 200 A	4 000 A	10 000 A	3 000 A	1 250 A	1 250 A	2 000 A	1 250 A
Max.rated short-time current	100 kA / 1 s	90 kA / 1 s	100 kA / 1 s	63 kA / 1 s	25 kA / 3 s	31,5 kA / 3 s	100 kA / 1 s	60 kA / 1 s
Max.quantity of cores	6 cores	6 cores	3-5 cores	3-5 cores	1-2 cores	1-2 cores	1 core	1 core
Standards	IEC, VDE, ČSN, PN, AS, BS, GOST, IEEE, CAN/CSA	IEC, VDE, ČSN, PN, AS, BS, GOST, IEEE, CAN/CSA	IEC, VDE, ČSN, PN, AS, BS, GOST, IEEE, CAN/CSA	IEC, VDE, ČSN, PN, AS, BS, GOST, IEEE, CAN/CSA	IEC, VDE, ČSN, PN, AS, BS, GOST, IEEE, CAN/CSA	IEC, VDE, ČSN, PN, AS, BS, GOST, IEEE, CAN/CSA	IEC, VDE, ČSN, AS, BS, GOST, IEEE, CAN/CSA	IEC, VDE, ČSN, AS, BS, GOST, IEEE, CAN/CSA
Applications	MV switchgear, compact secondary substations, motors & generators, drives, metal encl. capacitor banks, dry type transformers	MV primary air-insulated switchgear, motors & generators	MV air-insulated switchgear, motors & generators, drives, CSS, MECB, dry type transformers	MV primary gas-insulated switchgear, designed to fit MV cables, busbars or bushings	MV secondary gas- insulated switchgear, designed for MV cables in the cable compartments	MV air or gas switchgear, designed for MV cables or busbar incl. variant for 2x MV cables	MV air or gas insulated switchgear, designed for measurements of zero currents with multiple MV cables	MV air or gas insulated switchgear, designed for measurements of zero currents of MV cables
Features	Support type, opt.reconnection, capacitive divider, various dimensions, ribs, sealable sec. terminal cover	CT without primary conductor insulated for the MV application, opt. secondary reconnectable	High dimensions variability, inner Ø 33~500 mm, length 60~300 mm, opt. sec.reconnectable, sealable term. cover	High dimensions variability incl. variant for 2x MV cables or bushings, opt. sec. reconnectable, sealable sec. covers	Inner Ø 42, 50 or 60 mm, variant for self-powered relays, opt. secondary reconnection, opt. sealable sec. covers	Inner Ø 59, 69, 70, 85 or 110 mm, opt. secondary reconnection, BD 00 opt. sealable IP40 sec. cover	6x dimension variants, from inner Ø 200x300 mm up to 450x650 mm, opt. secondary reconnection	Designed for use with earth-fault protection relays. KOLMA single or multiratio variants. KOLA split-core type

	TJC/TJCH	TJP/TJPH	TDC	TJMC	TJMC/TJMP	TDMC		VT Guard Pro/-D
Max.rated voltage	TJC(H) 4 12 kV TJC(H) 5 17,5 kV TJC 6 27,5 kV TJC 7 40,5 kV	TJP(H) 4 12 kV TJP(H) 5 17,5 kV TJP 6 27,5 kV TJP 7 40,5 kV	TDC 4 12 kV TDC 5 17,5 kV TDC 6 25 kV	TJMC 7 40,5 kV	TJMP 4 12 kV TJMC 6 24 kV TJMP 6 24 kV	TDMC 6 24 kV	Rated operational voltage	100/110 V
Max.rated primary voltage	36 000: √3 kV	36 000: √3 kV	22 000 kV	36 000: √3 kV	22 000: √3 kV	22 000 kV	Max. oper. current	10 A/0.2 s
Min.rated voltage factor	1,9x Un / 8h	1,9x Un / 8h	1,2x Un / Continuous	1,9x Un / 8h	1,9x Un / 8h	1,2x Un / Continuous	Voltage range	0-110 V
Max.quantity of windings	3-4 windings	3-4 windings	2 windings	3 windings	3 windings	2 windings	Threshold voltage	20; 25; 30 V
Standards	IEC, VDE, ČSN, PN, AS, BS, GOST, IEEE, CAN/CSA	IEC, VDE, ČSN, PN, AS, BS, GOST, IEEE, CAN/CSA	IEC, VDE, ČSN, PN, AS, BS, GOST, IEEE, CAN/CSA	IEC, VDE, ČSN, PN, AS, BS, GOST	IEC, VDE, ČSN, PN, AS, BS, GOST	IEC, VDE, ČSN, PN, AS, BS, GOST	Time delay	0,4; 1,4; 2,4; 3,4s
Applications	MV switchgear, compact secondary substations, motors & generators, drives, metal encl. capacitor banks	MV switchgear, compact secondary substations, motors & generators, drives, metal encl. capacitor banks	MV air-insulated switchgear, motors & generators, drives, metal encl. capacitor banks	ABB MV primary SF6 gas-insulated switchgear, TJMC designed to fit switchgear cable and busbar compartments	ABB MV primary SF6 free gas-insulated switchgear, TJMC/P designed to fit switchgear cable and busbar compartments	MV gas-insulated switchgear, designed for the external power supply in new or retrofit installations	Applications	Designed for MV indoor single-pole VTs and open-delta connection. Protect VTs against ferroresonance phenomena
Features	Directly grounded sec. terminals with sealable cover, opt. reconnection, suitable for VT Guard Pro/Pro-D	In addition to TJC: ready for VT trucks, variable fuses and fuse-holder orientation, fuse w/wo indications	Directly grounded sec. terminals with sealable cover, opt. 2 primary voltage reconnection	Touch proof design, plug size 2 or 1/2 C cone primary interface, opt. secondary plug-in, sealable sec. terminals cover or socket	Touch proof design, primary ½ C cone, sealable sec. terminals cover, opt. build in fuse with various ratings	Touch proof design, 2x primary C cones, sealable sec. cover, working ambient temperature as low as -35°C	Features	Replace the dumping resistors, installed in the LV compartment, high reliability, redundancy circuits, Pro-D self-diagnosis

Related offering

Primary protection relays

Critical for grid safety and reliability, Primary Protection Relays continuously monitor the system to recognize abnormal conditions and instantly initiate cor-rective actions, preventing faults from spreading across the network.

Secondary protection relays

Specifically designed for the final stage of power delivery, Secondary Pro-tection Relays monitor the secondary distribution network to quickly detect and resolve local system abnormalities, ensuring safety and con-tinuous service.

Drives

ABB Drives is a global technology leader serving industries, infrastructure and machine builders with world-class variable speed drives, drive systems and packages.

Motor & Generators

Comprehensive range of solutions designed to energize the transformation of industries, enabling a more productive, sustainable future.

Compact secondary substations

A Compact Secondary Substation (CSS) is a type tested and arc tested assembly comprising an enclosure containing medium voltage (MV) switchgear, distribution transformers, low voltage (LV) switchboards, connections and auxiliary equipment to supply LV energy from MV systems.

MV Switchgear

ABB’s medium voltage switchgear are designed to connect and protect an evolving grid. Medium voltage electrical power distribution from generating stations to industries and consumers is divided into two main parts: primary and secondary distribution.

Frequently Asked Questions

Yes, ABB indoor instrument transformers are easy to install and friendly to maintain in most of the medium voltage indoor applications.

Maximum insulation voltage levels of ABB’s medium voltage indoor IEC instrument transformers are 40.5/95/200 kV.

ABB medium voltage indoor instrument transformers are typically used by original equipment manufacturers (OEMs), panel builders and non-panel builders’ applications, Engineering, Procurement and Construction (EPC) partners, utilities, as well as end-users. The transformers can be incorporated into installations or retrofit and upgrade projects.

Yes, ABB's medium voltage indoor IEC instrument transformers specifications can be tailored to market or customer needs. For example, the electrical ratings are customized every time.

Yes, ABB indoor medium voltage instrument transformers can be used in non-panel builders’ installations such as compact secondary substations, motors and generators, dry-type transformers, capacitor banks, metal-enclosed capacitor banks, generator circuit breakers, and others.

Yes, ABB's medium voltage indoor IEC instrument transformers comply with the latest versions of the IEC 61869 standards.

Yes, some of ABB's medium voltage indoor IEC instrument transformers can be manufactured compliant with the latest IEEE C57.13 or CAN/CSA-C61869 standards.

ABB’s medium voltage indoor medium voltage IEC instrument transformers have their own routine test reports according to the relevant standard as stated on the product’s label. Based on special request, ABB’s medium voltage indoor instrument transformers can be calibrated in an accredited laboratory.

ABB’s medium voltage indoor instrument transformers have an expected minimum lifetime of 30 years.

Yes, ABB has a global installed base of medium voltage indoor instrument transformers. Please feel free to contact our sales representatives for further information.

Yes, ABB has a global installed base of medium voltage outdoor instrument transformers. Please feel free to contact our sales representatives for further information.