Danfoss MBS 4251 Pressure Transmitter Installation Guide
- June 3, 2024
- Danfoss
Table of Contents
Danfoss MBS 4251 Pressure Transmitter
Installation guide
Pressure transmitters
MBS 4201, MBS 4251
Description / Application
Application: Pressure measurement in potentially explosive areas.
Approval: Exira IIC T5…T4 (MBS 42xx series) in accordance with ATEX
directive 2014/34/EU.
Function: Pressure transmitters type MBS 4201, MBS 4251 convert the
pressure measured to a 4 – 20 mA current signal.
Specifications
- Output current
- 4 – 20 mA
- Supply voltage
- 10 – 28 V
Safety specifications Electrical
Pressure specification
Measuring range| bar| 0 – 1| 0 – 1.6| 0 – 2.5| 0 – 4| 0 – 6| 0 – 10| 0 – 16| 0
– 25| 0 – 40| 0 – 60| 0 – 100| 0 – 160| 0 – 250| 0 – 400| 0 – 600
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---
Overload (Static)| bar| 6| 12| 24| 24| 60| 60| 150| 150| 300| 360| 600| 1200|
1500| 1500| 1500
Burst pressure| bar| 100| 100| 100| 100| 100| 100| 150| 150| 400| 800| 1200|
1200| 2000| 2000| 2000
Safety Instructions
The transmitter must always be supplied from an intrinsic safety barrier. All
national safety regulations must be complied with in connection with
installation, start-up and operation of Danfoss pressure transmitters type MBS
4201, MBS 4251. Furthermore, the requirements of the Declaration of Conformity
and national regulations for installation in explosion areas apply.
Disregarding such regulations involves a risk of serious personal injury or
extensive material damage.
Work in connection with the pressure transmitters mentioned must be performed
only by suitably qualified persons.
Ex requirements are fulfilled through certificates:
DEMKO 01 ATEX 127938X, IECEx ULD 12.00005X, UKEX UL22UKEX2660X
Special Ex protection instructions: In the event of damage to enclosure
or diaphragm, the pressure transmitter must be replaced. The end user must
ensure the installation is made in accordance to IEC/EN60079-25 and
IEC/EN60079-14.
WARNING –Potential Electrostatic Charging Hazard. The transmitter must only be
installed in surroundings with low wind speed, and where rubbing on the plug
is unlikely. Cleaning with a damp cloth is recommended. To avoid build -up of
electrostatic discharge it must be ensured the pressure connection of the
pressure transmitter is having a reliable connection to earth with an
impedance no exceeding 1 Ohm.
MBS transmitters contain 1.2 mph capacitance from any input terminal to earth.
Special conditions for safe use in accordance to the ATEX/IECEx
certificate:
For installations in which both the Ci and Li of the connected apparatus
exceeds 1% of Co and Lo parameters (excluding the cable),
then 50% of Co and Lo parameters are applicable and shall not be exceeded.
WARNING –Special precautions are necessary to reduce the risk due to
electro-static discharge. The transmitter must only be installed in
surroundings with low wind speed, and where rubbing the plug is unlikely.
Cleaning with a damp cloth is recommended.
The installation shall ensure that the resistance to earth of metallic parts
of the equipment enclosure is less than 1 GO hm.
The equipment does not provide 500 V isolation to earth as required by
IEC/EN60079-11: clause 6.3.13.
Installations of the pressure connection across boundary walls requiring
Category 1G equipment and a less hazardous area must
be gas tight as required by IEC/EN60079-26. Gaskets and seals used at the
pressure connection must be suitable for use with the process medium.
Demands on the medium:
Parts in contact with the medium are made of stainless steel, EN 1088-1 1.4404
(AISI 316L). The user is responsible for a careful analysis of all process
parameters when materials have to be specified and for ensuring the process
medium is neutral to stainless steel as some media can be corrosive. The end
user must ensure that the process connection is gas tight (as required by
IEC/EN60079-26) which may require the use of a suitable gasket/seal in
combination with the process connection to obtain a gas-tight connection.
Gaskets and seals used at the pressure connection, including those supplied
with the transmitters, must be determined as being suitable for use with the
process medium and process pressure/temperature before use and alternative
gasket material chosen if necessary. The end user must ensure the transmitter
pressure connection is tightened with the correct torque as required for the
specific thread type.
In case of problems please contact:
Danfoss A/S
DK-6430 Nordberg
Denmark
You find the EC-Type Examination Certificate at: www.ia.danfoss.com/ATEXcertificate
Installation/dimensions
Electrical connection
Cables must be specified for a minimum test voltage of 500 VAC between
conductor/earth, conductor/screen and screen/earth.
In addition, the total capacity and inductivity of the installation
(transmitter + cable) must be taken into consideration.
In Zone 0 an intrinsically safe type Ex ia circuit must be used and national
regulations for Zone 0 must be complied with. The pressure transmitter must
only be used in Zone 0 at atmospheric pressure between 0.8 and 1.1 bar and at
ambient temperatures between -20 and 50 °C.
Identification
