®
®
DMS Accessories
Order online at www.datel.com
These commercial grade, UL & CSA recognized, “donut
style” AC current-transformers (CT) provide an isolated 0-5A
output that can be used with DATEL’s ACA5 Series of digital
ammeters. Installation is straightforward: simply pass the load-
carrying conductor through the 5A CT’s primary window, and
then route its secondary’s leads through the ACA5-ammeter’s
built-in, low-burden, toroid sensor.
All models feature rugged, fully insulated construction, allow-
ing continuous operation with primary voltages up to 600Vac,
at line frequencies from 50 to 400Hz. Fourteen models are
available to enable accurate measurements from 50A through
2000A. When combined with DATEL’s ACA5 Series ammeters,
secondary lead-extensions may be used for those applications
where the CT cannot be installed in the immediate vicinity of
the ammeter.
General Specifications (All models)
Insulation Class
Frequency Range
Supplied Secondary Leads
600V, 10kV BIL full wave
50-400Hz
Flexible conductors, 24" (61cm)
16AWG (1.8mm
2
), UL Style 1015, 105°C
See Table 1 and technical note 6
See Table 1
E93779
LR89403
1.0 lbs. (454g)
5 Amp AC
Current Transformers
with DATEL’s ACA5 series ammeters). However, any CT can generate
potentially lethal voltages if its output current is suddenly interrupted.
For example, loose secondary connections can produce a condition
referred to as “inductive kick.” Inductive kick can generate extremely
high voltages across the open secondary connections.
Therefore, all connections made to a CT’s secondary leads must only
be performed with zero current flowing in the primary circuit. Never
operate a CT with its secondary circuit open and current flowing in
the primary.
2. CT Connections and Grounding:
Some applications require con-
necting one of the CT’s 5A output terminals to earth/chassis ground.
In the USA, consult the latest revision of the National Electrical Code
for more information.
After all mechanical assembly is completed, pass the 5A secondary
leads through the ACA5 ammeter’s built-in toroid, then connect the
two leads together as shown in Figure 1. For this connection, and
for connections involving lead extensions, pressure-style connectors
(commonly called “wire nuts”) are acceptable as long as they are rated
for the currents and voltages involved.
3. Installation:
CT’s must be installed in a manner that ensures no
excessive stresses are applied to the primary conductor that passes
through the CT or to the secondary circuit and its associated instru-
ments. Use plastic tie-wraps and/or other suitable non-conductive
restraining devices to secure the CT.
AC POWER
SUPPLY
ACA5-20PC-X-ACX
Max. Secondary Lead Length
See Table 1 and technical note 5
Rated Accuracy
Burden
UL FIle No.
CSA File No.
Weight
Basic Lightning Impulse Insulation Level (BIL): The insulation strength refer-
enced to the crest value of an impulse voltage-waveform which rises to a crest
value in 1.2 microseconds, then drops to 1⁄2 the crest value in 50 microseconds.
Tehnical Notes
IMPORTANT! To ensure safe and reliable operation, Current Trans-
formers and associated equipment must be installed and serviced
by qualified technical personnel. Never open the CT’s secondary
connections while the primary is energized. Open CT secondary
wiring can generate potentially lethal voltages when the primary
circuit is energized. Contact DATEL if you have any doubts
regarding the installation or operation of any of our ac-mains
measurement instruments and accessories.
1. CT Precautions:
In normal operation, a 5A current transformer’s
secondary circuit operates at a relatively low voltage due to its closed-
loop, low burden configuration (essentially zero Ohms when used
TO AC LOAD
TB1
A
B
L1
5A CURRENT
TRANSFORMER
(see technical notes)
0-5A
OUTPUT
Figure 1. Typical Connections
DATEL, Inc., Mansfield, MA 02048 (USA)
•
Tel: (508)339-3000, (800)233-2765 Fax: (508)339-6356
•
E–mail: sales@datel.com
•
Internet: www.datel.com
DMS Accessories
5 AMP AC CURRENT TRANSFORMERS
4. Reference Documentation:
Prior to connecting CTs to any measure-
ment device (analog or digital), relay, or other apparatus, be sure to
thoroughly review the applicable device’s technical documentation (for
example, DATEL’s ACA5-20PC product data sheet). In particular, make
sure the CT’s ratings meet the requirements of your application.
5. Secondary Lead Extensions:
When calculating the total burden
imposed on a CT’s 5A output, DATEL’s ACA5 digital ammeters’ input
impedance is negligible and can be assumed to be zero Ohms. In
many applications, the length of secondary wiring can be increased
up to the value specified in Table 1 without adversely affecting perfor-
mance.
In order to achieve the specified accuracy, the maximum permissible
burden must not exceed the value shown in Table 1. When used with
ACA5 ammeters, the total burden is the sum of the resistance of the
CT’s 24” leads and any lead-extensions. Make sure all connections are
securely tightened and properly strain relieved. If terminal blocks are
used for intermediary connections, refer to the manufacturer’s torque
recommendations.
Table 1 lists general guidelines for adding lead extensions when using
DATEL’s ACA5-Series ammeters as the readout device. The lengths in
Table 1 assume the lead extensions are 16AWG. Stated dimensions
are one-way distances between the ACA5 and the CT. Make sure
all secondary extensions meet or exceed the specifications of the
CT’s built-in leads. In order to minimize external noise pick up, lead
extensions should be as kept short as possible.
6. Accuracy:
The indicated accuracy specifications are valid as long as
the total secondary burden does not exceed the value in Table 1’s
burden column. Accuracy measurements are taken at 100% primary
current, using a resistive burden and a nominal line frequency of 60Hz.
7. Polarity:
CTs are marked with ‘H1’ (primary) and ‘X1’ (secondary)
polarity indicators. When a CT’s only function is to measure amperes,
polarity markings can be disregarded. However, correct polarity is
mandatory in applications in which the phase relationship between
two currents is involved (watt or watt-hour meters are two examples
of polarity sensitive applications). Refer to the respective instruments’
documentation for more information.
8. Thermal Rating Factor:
The thermal rating factor denotes the amount
by which the primary current can be increased on a continuous
basis over its rated value without exceeding the CT’s maximum tem-
perature rise.
The formula below can be used to calculate thermal rating factors at
temperatures above 30°C.
(85 - NAT)(RF)
2
NRF =
NAT
NRF = Rating Factor at New Ambient Temperature
RF = 30°C Rating Factor
NAT = New Ambient Temperature
Example:
Find the 55°C. thermal rating factor of a 2000:5 CT whose
30°C rating factor is 2.0
(85 - 55)(2)
2
NRF =
55
= 1.48
Table 1. Selection Guide
DATEL Part No.
39-3681401
39-3681402
39-3681403
39-3681404
39-3681405
39-3681406
39-3681407
39-3681408
39-3681409
39-3681410
39-3681411
39-3681412
39-3681413
39-3681414
Current Ratio
(Amps)
50:5
75:5
100:5
150:5
200:5
250:5
300:5
400:5
500:5
600:5
750:5
1000:5
1500:5
2000:5
Accuracy
(@ 60Hz)
±2%
±2%
±1%
±1%
±1%
±1%
±1%
±1%
±1%
±1%
±1%
±1%
±1%
±1%
Burden
VA (Ohms)
1.5 (0.06)
3.0 (0.12)
3.0 (0.12)
6.0 (0.24)
8.0 (0.32)
10.0 (0.40)
12.5 (0.50)
12.5 (0.50)
20.0 (0.80)
10.0 (0.40)
10.0 (0.40)
10.0 (0.40)
12.5 (0.50)
15.0 (0.60)
Lead Ext.
Feet (Meters)
4 (1.2)
10 (3.0)
10 (3.0)
20 (6.1)
30 (9.1)
40 (12.2)
50 (15.2)
50 (15.2)
80 (24.4)
40 (12.2)
40 (12.2)
40 (12.2)
50 (15.2)
60 (18.3)
Thermal Rating Factor
(@30°C)
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
2.0
2.0
2.0
2.0
2.0
Underlined digit(s) of part number corresponds to the matching ACA5 ammeter. For example, part number 39-3681403 is used with an
ACA5-20PC-3 ammeter to measure currents up to 100.0A.
DATEL, Inc., Mansfield, MA 02048 (USA)
•
Tel: (508)339-3000, (800)233-2765 Fax: (508)339-6356
•
E–mail: sales@datel.com
•
Internet: www.datel.com
2
5 AMP AC CURRENT TRANSFORMERS
DMS Accessories
Mechanical Specifications: Inches (mm)
1.42 (36.1)
X1
2.69
(68.3)
1.25
(31.8)
DIA
H1
Models: 39-3681401 – (50:5)
39-3681402 – (75:5)
39-3681403 – (100:5)
39-3681404 – (150:5)
39-3681405 – (200:5)
39-3681406 – (250:5)
1.10 (27.9)
X1
3.56
(90.4)
1.56
(39.6)
DIA
H1
Models: 39-3681407 – (300:5)
39-3681408 – (400:5)
39-3681409 – (500:5)
1.13 (28.7)
X1
4.50
(114.3)
3.00
(76.2)
DIA
H1
Models: 39-3681410 – (600:5)
39-3681411 – (750:5)
39-3681412 – (1000:5)
39-3681413 – (1500:5)
39-3681414 – (2000:5)
®
®
DS-0516 5/02
DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151
Tel: (508) 339-3000 (800) 233-2765 Fax: (508) 339-6356
Internet: www.datel.com
Email: sales@datel.com
DATEL (UK) LTD. Tadley, England Tel: (01256)-880444
DATEL S.A.R.L. Montigny Le Bretonneux, France Tel: 01-34-60-01-01
DATEL GmbH München, Germany Tel: 89-544334-0
DATEL KK Tokyo, Japan Tel: 3-3779-1031, Osaka Tel: 6-6354-2025
DATEL makes no representation that the use of its products in the circuits described herein, or the use of other technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein do
not imply the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without notice. The DATEL logo is a registered DATEL, Inc. trademark.