
DMS Accessories
5 Amp AC Current Transformers
www.murata-ps.com
Technical enquiries
email: sales@murata-ps.com, tel:
+1 508 339 3000
MPM_DMS-CT.A01
Page 1 of 4
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-amme-
ter’s built-in, low-burden, toroid sensor.
All models feature rugged, fully insulated construction, allowing 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.
TECHNICAL NOTES
~
Basic Lightning Impulse Insulation Level (BIL): The insulation
strength referenced to the crest value of an impulse voltage-
waveform which rises to a crest value in 1.2 microseconds, then
drops to the crest value in 50 microseconds.
Insulation Class
Frequency Range
Supplied Secondary
Leads
Max. Secondary Lead
Length
Rated Accuracy
Burden
UL FIle No.
CSA File No.
Weight
600V 10kV BIL full wave
~
50-400Hz
Flexible conductors, 24"
(61cm) 16AWG (1.8mm2),
UL Style 1015, 105°C
See Table 1 and technical
note 5
See Table 1 and
technical note 6
See Table 1
E93779
LR89403
1.0 lbs. (454g)
IMPORTANT! To ensure safe and reliable operation, Current Transformers and asso-
ciated 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 cir-
cuit 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 with DATELs 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 connecting 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 instruments. Use plastic tie-wraps and/or other suitable non-conductive
restraining devices to secure the CT
Figure 1. Typical Connections
TB1
A
B
ACA5-20PC-X-ACX
L1
AC POWER
SUPPLY
5A CURRENT
TRANSFORMER
TO AC LOAD
0-5A
OUTPUT
(see technical notes)
General Specifications (all models)