User Documentation

Operating Manual /
Installation Guide
Low Voltage-Current Transformer
Model Range CTB
Measurement ranges:
Primary current: 50 up to 2500A AC
Secondary current: 1A or 5A
Indication:
Before initial operation we ask you to pay full
attention to these assembling instructions in order
to guarantee the reliability and to ensure the
performance of the device.
Please see an updated version of this datasheet on
our homepage www.mbs-ag.com.
MBS AG
Eisbachstraße 51
74429 Sulzbach-Laufen
Tel. [phone]
Fax. [phone]
Functional Description
Current transformers of the CTB model range are inductive,
single-conductor current transformers operating according
to the transformer principle. Due to the applied measuring
principle, current transformers of this type may only be
installed in alternating current (AC) networks.
Technical Parameters
Primary rated current: 50 … 2500 A AC
Secondary rated current: 5A or 1A
Accuracy class: 1
Over current limiting factor: FS5 / FS10
(see name plate)
Rated frequency: 50 / 60Hz
Rated thermal
continuous current Id: 1,2 x In
Rated thermal
short-time current Ith: 60 x In, (max. 100 kA), 1 s
Operating temperature range: -5°C ≤ ϑ ≤ +50°C
(0…95% relative humidity,
non condensing!
Storage temperature range: -25°C ≤ ϑ ≤ +70°C
Connection clamps: WAGO Cage-Clamp
max. 4,0 mm²
Applied standards: DIN EN 60044-1 (12/2003)
VDE 0414-1 (12/2003)
File no. of UL-approval: E336996 (2010)
Isolation Characteristics
Maximum voltage for
electrical utilities: 1,2 kV, Ueff
(maximum phase-phase-voltage)
In accordance with IEC 61010-1 under condition of:
Overvoltage category III
Pollution degree 2
Heterogeneous electrical field
Rated power frequency withstand voltage
(Isolation test voltage
primary conductor against
measuring output: 6 kV, Ueff, 50 Hz, 1 min.
UL-housing classification: UL94-V0
In order to avoid personal and material
damage the following assembling steps
must be performed by qualified and
trained personnel only.
If the secondary circuit is operated
without a burden/load (open) high
voltages may appear. These voltage
values are dangerous for persons as
well as for the functional reliability of
the current transformer.
It is forbidden to operate the current
transformer without a secondary
circuit (open)!
Environmental Instruktion
When the product has reached its “end of life“,
it must be recycled. Please pass it to an
electrical waste disposal. Do not dispose as
unsorted municipal waste!
This product was developed and
manufactured in accordance with the
applicable regulations (IEC 61010, IEC
61869) and meets the requirements of
the low voltage guideline 2006/95/EG
Accessory: Quick-fix