MTLCertificate Number Baseefa09ATEX0155 Issue 6

transformers that provide galvanic isolation between the hazardous and non-hazardous area circuitry, zener diode chains

and resistors providing voltage and current limitation. The above, together with other electronic components are mounted

on a single printed circuit board (PCB) and housed in a moulded plastic enclosure. Polarised plugs and sockets are

provided for hazardous and non-hazardous area connections. LED indication is fitted to indicate power-on.

The MTL454IS Single Channel Repeater Power Supply, 4/20mA for 'Smart' Transmitters is a depopulated version ofthe

MTL4544S and has only one channel populated.

The MTL4544D Repeater Power Supply, 4/20mA for 2 or 3 Wire Transmitters with two outputs is designed to provide a

floating d.c. supplies for energising a 2 or 3-Wire 4/20mA Transmitter located in the hazardous area and repeat the current

on two channels in the non-hazardous area, whilst restricting the transfer of energy from the unspecified non-hazardous

area apparatus to the intrinsically safe circuits by means of limitation of current and voltage. The apparatus also allows bidirectional signal communication between the hazardous and non-hazardous area by the connection of a hand-held

communicator (HHC). The apparatus uses the same printed circuit board and enclosure as the MTL4544S but is populated

with only one hazardous area transmitter connection and two non-hazardous area outputs fitted.

The MTL454IT Single Channel Repeater Power Supply, 4/20mA for 2 or 3-Wire Transmitters is similar to the

MTL454I S but is fitted with different voltage and current limitation components and therefore has different output

parameters.

MTL4541S, MTL4544S & MTL4544D Input / Output Parameters

Non-hazardous Area Terminals 8, 9, 11, 12, 13 & 14

Urn 253V Lm.S.

The apparatus is designed to operate on non-hazardous area terminals 8, 9, 11, 12, 13 & 14 from a d.c. supply voltage of

up to 35V.

Hazardous Area Terminals 2 W.r.t. 1 (Channel 1)

Or

Hazardous Area Terminals 5 W.r.t. 4 (Channel 2 - MTL4544S model)

28V

93mA

O.65W

o

o

Hazardous Area Terminals 3 W.r.t. 1 (Channel 1)

Or

Hazardous Area Terminals 6 w.r.t. 4 (Channel 2 - MTL4544S model)

1.1V

53mA

15mW

UI

I 1

30V

121mA

C1

L1

o

o

Although the apparatus does not comply with the simple apparatus requirements of Clause 5.7 of EN 60079-11: 2012,

when terminals 3 W.r.t. 1 or terminals 6 W.r.t 4 (MTL4544S model only) are connected in an intrinsically safe circuit the

internal stored energy, voltage and current of the interface will not add more than the values specified in Clause 5.7 of

EN 60079-11: 2012 to the parameters ofthe circuit into which it is connected.

When an external intrinsically safe source is connected to these terminals it should have a source resistance of Uj / Ii and

the capacitance and either the inductance or inductance to resistance ratio (L/R) ofthe hazardous area connections must not

exceed the values detailed in the certificate of the intrinsically safe source. Hazardous area terminals 2 and 5 must not be

used when the source is connected.

Hazardous Area Terminals 2 W.r.t. 3 (Channel 1)

Or

Hazardous Area Terminals 5 W.r.t. 6 (Channel 2 - MTL4544S model)

28V

87mA

0.61W

o

o

Each channel must be considered as a separate intrinsically safe circuit.

Load Parameters

The capacitance and either the inductance or inductance to resistance ratio (L/R) of the hazardous area load connected

must not exceed the following values for either channel:

GROUP CAPACITANCE INDUCTANCE OR LIRRATIO

(J1F) (mH) (J1H/ohm)

Hazardous Area Terminals 2 w.r.t. 1 or 5 W.r.t. 4 (MTL4544S only)

IIC 0.083 4.2 56

IIB* 0.65 12.6 210

IIA 2.15 33.6 444

I 3.76 53.7 668

Hazardous Area Terminals 3 W.r.t. 1 or 6 W.r.t 4 (MTL4544S only)

IIC 100 12.8 2,438

IIB* 1,000 47.8 8,932

IIA 1,000 104.7 18,140

I 1,000 156.2 28,229

Hazardous Area Terminals 2 W.r.t. 3 or 5 W.r.t. 6 (MTL4544S only)

IIC 0.083 4.9 59

lIB* 0.65 20.0 222

IIA 2.15 40.9 469

I 3.76 59.1 710

* Group lIB parameters also applicable for associated apparatus [Ex ia Da] IIIC

Notes:

1) The above load parameters apply when one ofthe two conditions below is given:

- the total Lj ofthe external circuit (excluding the cable) is < 1% ofthe Lovalue or

- the total Ci ofthe external circuit (excluding the cable) is < 1% ofthe Co value.

The above parameters are reduced to 50% when both ofthe two conditions below are given:

- the total Lj ofthe external circuit (excluding the cable) is 1% ofthe Lovalue and

- the total Cj ofthe external circuit (excluding the cable) is 1% ofthe Co value.

The reduced capacitance ofthe external circuit (including cable) shall not be greater than I/-lF for Groups IIB, IIA

& I and 600nF for Group IIC.

MTL4541T Input / Output Parameters

Non-hazardous Area Terminals 8, 9, 11, 13 & 14

Urn 253V r.m.s.

The apparatus is designed to operate on non-hazardous area terminals 8, 9, 11, 13 & 14 from a d.c. supply voltage of up to

35V.

Hazardous Area Terminals 2 W.r.t. 1

22V

167mA

0.92W

o

o

Hazardous Area Terminals 3 W.r.t. 1

1.0V

53mA

14mW

30V

121mA

o

o

Although the apparatus does not comply with the simple apparatus requirements of Clause 5.7 of EN 60079-11: 2012,

when terminals 3 W.r.t. 1 are connected in an intrinsically safe circuit the internal stored energy, voltage and current ofthe