MTL Instruments MA15 Specifications

• 18kA surge protection and RFI

filtering

• Protects panel loads up to 15 Amps in

series, unlimited Amps in parallel

• Suitable for AC or DC application

• Thermal and short circuit protection

• LED status indication feature

• 10 year product warranty

• UL1449 3rd Edition

technical datasheet

MA15 Series

AC and DC power surge suppressor and filter

The MA15 Series of surge protection devices
protects electronic equipment and computer
networks against the effects of ‘noise pollution’
induced in power supplies. MA15 units ‘clean
up’ the effects of industrial noise and surges
caused by lightning, switching devices, thyristor
controls, transmission system overloads and
power-factor correction circuits.

Industrial control systems utilizing
programmable logic controllers (plc) and
industrial computers are particularly vulnerable
due to the aggressive electrical environments for
which they are intended, such as process plants,
factories and water treatment sites. Although
industrial computers and plcs are designed to
be rugged, the extra protection provided by the
DIN rail mounting MA15 units is critical. Ideally
suited for protecting panel mounted equipment
and typically used in the controls section of a
motor control centre (MCC), the MA15 range
provides surge and RFI protected power.

With a unique ‘three-stage’ combination
of protection elements, these units suppress

conducted RFI and voltage surges. The circuit
elements are first, surge clipping components
to absorb transient surges that may otherwise
damage equipment, second a filter to suppress
noise in the system and third, ‘ring’ suppression.
The third of these prevents surges causing
the filter to ‘ring’ (oscillate) under low load
conditions – an effect that actually accentuates
interference in most commercially available
filters.

Suitable for AC or DC application, MA15
units reduce both electromagnetic emissions
and the susceptibility of the associated
equipment to emissions from other sources.
MA15 devices also offer ultimate installation
flexibility. To protect circuits rated 15A or less,
MA15 devices should be installed in series. To
protect higher current circuits, simply install the
MA15 in parallel.

An LED status indication facility is
standard with the MA15 units. This displays
both ‘power on’ and that protection is present.
Thermal fusing is also incorporated into each
18kA rated device as an additional safety
feature. MA15 units also offer short circuit
protection for added peace of mind.

MA15 devices are UL 1449 Recognized
Components (certified by UL for both US

and Canadian requirements) and exceed the
requirements of IEC 61000-4-5. As MA15 units
suppress conducted RFI and voltage surges they
enable associated equipment to comply with
this aspect of European ‘CE’ mark standards.

901-108 Rev J 110511

www.mtl-inst.com [e-mail]

SPECIFICATION

All figures typical at 77°F (25°C) unless otherwise stated

Maximum surge current

18kA (8/20µs) per mode

Maximum leakage current

<0.3mA

Maximum continuous operating current

120V @ 15A 240V @ 10A series connection
Unlimited Amps in parallel

Working voltage

AC DC
MA15/D/1/SI 120V, 47-63Hz 140V
MA15/D/1TT/SI 120V, 47-63Hz 140V
MA15/D/2/SI 240V, 47-63Hz 280V
MA15/D/2TT/L 240V, 47-63Hz 280V

Maximum continuous operating voltage

25% above nominal

Limiting voltage

@ 500A ring
120V/140V versions 295V
240V/280V versions 356V
@ 500A 8/20µs
120V/140V versions 320V
240V/280V versions 800V
@ 3kA 8/20µs
120V/140V versions 396V
240V/280V versions 975V
@ 10kA 8/20µs
120V/140V versions 585V
240V/280V versions 1210V

Maximum attenuation (typical)

-55dB @ 100MHz

Modes protected

L-N, L-E, N-E

Ambient temperature limits

–40°F to +185°F (working)
–40°C to +85°C (working)

Humidity

95% RH (non-condensing)

Casing

Polymide-PA, with G- or T-section
(Top-hat) DIN-rail mounting foot
UL94-V0
Connectors
Screw terminal

Terminals

0.1 inch2 (2.5mm2 ) 12 AWG

Mounting

G- or T-section (‘Top-hat’) or 1.4 inch
(35mm) DIN rail

Weight

3.53oz (100g)

Dimensions

See figure 1

EMC compliance

BS EN 60950 : 1992
BS EN 61000-6-2 : 1999
LED Indication
Green LED on Protection present
Green LED off Internal failure

Installation

Typical wiring connections for MA15 Series
devices are indicated in figure 2. The grounding
of the surge protector and the protected
equipment is very important and, if possible,
should be accomplished as illustrated.

Please note that the unit is marked Line
and Load and it is important that the unit is
installed with the Line side connected to the
incoming power and the Load connected
to the equipment to be protected. For
parallel application however, the Line side is
connected to the incoming power and the

Load left unconnected.

Figure 1 Dimensions

Series Connection

Current <15A

Parallel Connection

Current >15A

Figure 2 Installation

Approvals

Country Standard/Authority Approved for Product

United States
Canada

United States
Canada

India Petroleum & Explosives

NOTE: The above approvals do not apply to the MA15/D/2TT/L and DC applications.

UL 1449
Recognized Component

UL 1449
Recognized Component
UL1604

Safety Organisation
(PESO)

AC Power Product MA15/D/1/SI,

MA15/D/2/SI

Hazardous Locations
Class I, Division 2

MA15/D/1/SI,
MA15/D/2/SI

Groups A, B, C and D

EEx ia MA15/D/1/SI

MA15/D/2/SI

The given data is only in tended as a product des cription and should not b e regarded as a legal warranty o f properties
or guarantee. I n the interest of fu rther tech nical develop ments, we reserve th e right to make design c hanges.

EUROPE (EM EA): [phone] THE AMER ICAS: [phone] ASIA-PACIF IC: [phone]

[e-mail] [e-mail] [e-mail] 901-108 Rev J 110511