MTL Instruments TP32 Specifications

Technical data

MTL surge protection

MTL TP32 range

Protects transmitters and
smart transmitters from
induced surges and transients
on fieldbus cabling

• TP32 is a fieldbus specific surge protector

designed to meet the requirements of IEC
61158-2:2004 & ANSI/ISA-50.02-2:1992

• TP32-T includes a terminator for fieldbus

in addition to surge protection

• Easy and direct mounting — screws into

spare conduit entry on the transmitter

• Parallel connection ensures ‘transparent’

operation — zero voltage-drop across device

• ATEX approved, Certified FISCO Terminator

• 10 year product warranty

July 2015
EPS 901-114 Rev L

The TP32 surge protection device is specifically designed to protect
process transmitters and devices on fieldbus systems. The TP32 builds
on the high specification of the acclaimed TP48 range to provide a level
of surge protection for fieldbus transmitters in excess of the optional
transient protection available from some transmitter manufacturers.

The terminated TP32-T has the same protection circuit as the
standard product, but also includes a F
circuit. This unique combination eliminates the need to purchase
and install additional termination circuitry for the FF segment. The
TP32-T provides excellent transient protection control and terminates
the bus segment in one simple-to-install package. The termination
circuit is designed to the requirements described in ANSI/ISA 50.02-2.
Note: Two terminators are required per bus segment.

The all-important earth connection is made via the casing of the
transmitter, negating the need for a separate earth connection or a
ground stake at the transmitter. In operation, the TP32 makes sure
that the transmitter electronics are never exposed to damaging
transients between the lines and ground. Any surge current appearing
as a series-mode or common-mode transient is converted into a
common-mode voltage whereupon the transmitter electronics are
temporarily raised to some higher voltage level before ‘floating’ down
automatically (and without damage) to resume normal operation.

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oundation fieldbus™ termination

Measurement Technology Limited,
Great Marlings, Butterfield, Luton
Beds, LU2 8DL, UK.
Tel: + 44 (0)1582 723633 Fax: + 44 (0)1582 422283
E-mail: [e-mail]
www.mtl-inst.com

© 2015 MTL
All Rights Reserved
Publication No. EPS 901-114 Rev L
July 2015

The TP32 protection network is a hybrid design consisting of high­power, solid state electronics and a gas discharge tube which is
capable of diverting surges up to 20kA. Encased in a 316 stainless
steel enclosure, the TP32 exhibits unparalleled mechanical durability
providing years of maintenance-free operation in harsh environments.
The enclosure is available threaded for all the common conduit entries.
Versions are available for 1/2” NPT, 20mm ISO, and G 1/2” (BSP 1/2
inch) threaded entries.

Installation is simple and can easily be carried out retrospectively
to existing installations. By connecting in parallel to the transmitter
circuit the TP32 does not interfere with the normal operation of the
bus – passing AC or DC signals without adding increased voltage drop
across the segment while consistently diverting surge currents safely
to ground and clamping output voltage to safe levels.

Approvals for intrinsically safe, flameproof, explosion-proof and
non-incendive operation are available, in all gas groups and apparatus
temperature classifications up to T6.

The TP32 is designed to meet the requirements of IEC 61158­2:2000 and ANSI/ISA-50.02-2:1992 for 31.25kB/sec systems as used
by Foundation fieldbus™, PROFIBUS-PA and WorldFIP.

MTL TP32 range

July 2015

FIELD DEVICE PROTECTION USING TP32

Non-Hazardous Installation

Install a TP 32 on every instrument critical to the operation of the process
system.

Install TP 32 on each instrument with a spur length greater than 50m
horizontal and 10m vertical.

For a detailed risk analysis (to minimize the number of protectors required)
and guidance for total fieldbus system protection, please see TAN 1010.

Hazardous Area Explosion-proof, Flameproof / Increased Safety

Install TP 32-X-NDI (where X = thread t ype) on every instrument critical to
the operation of the process.

Install TP 32-X-NDI on each instrument with a spur length greater than 50m
horizontal, 10m vertical.

See TAN 1010 for details of total fieldbus protection.

Hazardous Area Intrinsically Safe System; FISCO

Install TP 32-X-NDI (where X = thread t ype) on every instrument critical to
the operation of the process.

Install TP 32-X-NDI on each instrument with a spur length greater than 50m
horizontal, 10m vertical.

See TAN 1010 for details of total fieldbus protection.

NOTE: The TP32 NDI is FISCO compatible.

NOTE: Protection at the host end of the trunk is mandatory, see FP32 datasheet and TAN 1010 for more information.

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