MTL Instruments mSA Specifications

• Easy installation — ready boxed in

IP65 weatherproof housing with cable
glands

• Multi-stage hybrid protection circuitry

— high surge absorption capability

• Single and dual pair versions available

• Range of voltage ratings covering all

process related signals

• 10 year product warranty

technical datasheet

mSA Series

Protects electronic equipment and systmes against surges on signal and
data cabling

The mSA Series prevents surges and
transient overvoltages conducted through
data and signal cabling from causing damage
to electronic systems such as instrumentation
control panels, telemetry outstations and fire
and security alarm installations.

Isolated applications are particularly at risk,
e.g. unmanned water monitoring stations,
as they are regularly exposed to lightning
activity and therefore suffer frequent damage.
Telematic mSA Series surge protection
devices increase system reliability, prevent
costly damage to equipment and reduce
maintenance costs at remote sites.

Sophisticated hybrid circuitry protects
vulnerable equipment without affecting normal
operation, passing ac or dc signals with little
attenuation while diverting surge currents
safely to earth and clamping output voltages
to safe levels.

Modules with a comprehensive range of
voltage ratings (6V, 16V, 30V, 51V and 75V

versions) cover all process related signals
such as RTDs, THCs and 4-20mA loops.

Single and dual pair versions allow installation
flexibility and are ideal for 3 and 4-wire RTD
applications.

These self-contained units provide a
weatherproof barrier especially suitable
for exposed locations. The whole circuit is
assembled inside an IP65 (NEMA 12 and

13) enclosure which is ready fitted with
cable glands and an external earth stud, so
installation is very simple. Connections for the
mSA Series are via screw-clamp terminals.

The mSA design incorporates test points to
enable fast maintenance checks. Removable
links enable the ‘high’ and ‘low’ energy
sections to be tested independently.

The mSA Series is also suitable for Telecom
applications — private wire installations can

be protected using the standard mSA range.
Public Switched Telephone Networks (PSTNs)
are served by the specifically designed
mSAPN Series which utilises the same rugged
enclosure as the mSA range. mSAPN devices
are available with either single or dual line­pair protection networks, like the mSA units,

and are supplied with IDC-type terminals.
An IDC insertion tool is supplied for ease of
convenience.

901-135 Rev F 170210

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

Specification

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

Maximum surge current

10kA (8/20µs waveform)

Nominal resistance per line

mSA’s 43 ohms
mSAPN’s 5 ohms

Ambient temperature limits

-40°C to +80°C - working

-40°F to +176°F - working

Humidity

5% to 95% RH (non-condensing)

Enclosure

Plastic ABS
IP65 (NEMA 12 and 13)
Ready fitted with cable glands

Connectors

mSA’s screw-clamp terminals
mSAPN’s IDC terminals

Terminals

mSA’s 2.5mm2 (12AWG)
mSAPN’s IDC terminals (tool provided)

Mounting

via M5 external earth stud

Weight

220g (7.8oz) approx.

Dimensions

See figure 1

EMC compliance

To Generic Immunity Standards
BS EN 50082, part 2 for industrial
environments

R&TTE compliance

BS EN 50082-2: 1995
BS EN 41003: 1999

LVD compliance (mSAPN)

BS EN 41003: 1999

Model Lines Working

voltage

Rated load

current load

current

Maximum

leakage

current

Maximum

continuous

operating

Limiting

voltage

Bandwidth

voltage

(mA)

(µA)

(V)

(V)

mSA16/1 1 pair 13.5 180 5 16 40 380kHz

mSA30/1 1 pair 25.5 340 5 30 60 500kHz

mSA51/1 1 pair 43.5 400 5 51 100 580kHz

mSA75/1 1 pair 64 400 5 75 150 600kHz

mSA06/2 2 pairs 5.5 70 1000 6 30 220kHz

mSA16/2 2 pairs 13.5 180 5 16 40 380kHz

mSA30/2 2 pairs 25.5 340 5 30 60 500kHz

mSA51/2 2 pairs 43.5 400 5 51 100 580kHz

mSA75/2 2 pairs 64 400 5 75 150 600kHz

mSAPN/1 1 pair 180 N/A 10 200 250 10MHz

mSAPN/2 2 pairs 180 N/A 10 200 250 10MkHz

Definitions of terminology used in table
1 Working voltage
Maximum voltage between lines or lines/
earth for the specified leakage current
2 Maximum leakage current
Maximum current drawn by the SPD at the
working voltage

3 Maximum continuous operating voltage
Maximum voltage that can be applied to
the protected terminals without damage
4 Limiting voltage
Peak output voltage after injection of test
impulse from 6kV/3kA combination
waveform generator (often known as
‘let-through’ voltage

inStallation

Figure 2 shows the installation for a typical
telemetry outstation. All cables entering the
telemetry cabin should be fitted with surge
protection devices (SPDs) to prevent lightning
currents entering telemetry equipment. mSA30
devices can be used for 4-20mA applications
whilst PSTN lines should be protected using
the mSAPN.

Correct earthing is essential for optimum
protection against lightning induced
overvoltages. The units should be bonded
to the incoming mains power supply using a
short length, preferably less than 1 metre, of

2.5mm2 or greater thickness cable.

Model Body Certificate

mSA06 ­mSA51

mSAPN Oftel

ODTR

NS/2190/2/F/450911

BT

NS/G/1235/W/100025

PTT

NL 93040203
(The Netherlands)
DOC 19/99 (Eire)

Figure 1 Dimensions

Figure 2 Installation and earthing for typical control systems

approvalS

Note: Approvals now superseded by CE marking under the R&TTE Directive.
See ‘Specification’ section for further information.

The give n data is only inten ded as a product de scription an d should not be reg arded as a lega l warranty of pro perties
or guara ntee. In the i nterest of fu rther te chnica l develop ments, we re serve the r ight to make d esign cha nges.

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

[e-mail] [e-mail] [e-mail] 901-135 Rev F 170210