Danfoss MP 55E Pressure Switch

Installation Guide

Refrigerants

The MP 55E is suitable for use with the following refrigerants:

R1270 (propylene)
R290 (propane)
R600 (butane)
R600a (isobutane)

For a complete list of approved refrigerants, visit www.products.danfoss.com and search for individual code numbers.

Safety Warning: This product is validated in accordance to EN 60079-0:2012 + A11:2013 and ignition risk is evaluated in accordance to EN 60079-11:2012. See safety requirements at the end of this instruction.

Technical Data

Type	Operation range LP	PS/MWP [bar]	P_test
MP 55E	-1 - 12	17	22

Electrical Connection

The MP-E pressure switch, when placed in an explosive zone, must be wired through a reliable Ex zener barrier located outside the explosive zone. This ensures insufficient energy supply to prevent ignition of the surrounding atmosphere from electrical sparks or component heating.

Equipment used for electrical load limiting must be approved for the specific zone concerned.

Cables and cable entries must be approved for the application and should not contact sharp edges. Cables must be secured with adequate stress relief to prevent pulling forces from reaching the terminals.

Note: A system may be classified in different zones for different parts.

Intrinsic Safety Protection Method

For intrinsically safe applications, the MP-E pressure switch requires a certified Ex ic barrier (product matching) that satisfies the input parameters.

EX - zone:

Non EX - zone:

Electrical data for intrinsically safe specification (for all MP-E types):

Pi max: 1 W
Ui max: 30 V
Ii max: 0.1 A
Ci max: 0.5 nF
Li max: 0.2 μH

Product marking: Ex II 3G Ex ic IIB T6 Gc

Safety Requirements

The MP-E can be applied on systems with R1270 (propylene), R290 (propane), R600 (butane), R600a (isobutane) as the working fluid. For countries where safety standards are not an indispensable part of the safety system, Danfoss recommends the installer to obtain third-party approval of the system containing flammable refrigerant. Follow specific selection criteria stated in the datasheet for these particular refrigerants.
The refrigeration system must always comply with European Ex installation standard, EN 60079-14, any local directive and legislation, and other applicable regulations.
The MP-E switch must be used only with reliable means of limiting voltage and current to prevent sparks between contact surfaces. Electrical load limiting equipment must be approved for use in the zone concerned.
Approved cables and cable entries must be used. Cables must not contact sharp edges. Cables must be connected with adequate stress relief to prevent pulling forces from reaching the terminals.
In systems with pressure pulsations, these must be effectively damped to prevent bellows fatigue. The cycle frequency and vibration level for the MP-E switch must be kept as low as possible.
Regularly check the function of the MP-E switch.
Only apparatus designed, constructed, and released by Danfoss must be used. Danfoss is not responsible for alterations or misuse of the pressure switches.
Prevent overload of the MP-E switch. Overloaded or damaged apparatus must be exchanged.
Only authorized persons certified in installing and maintaining refrigeration systems may perform installation, maintenance, and exchange of the switch.
Use only appropriate tools.
Dispose of the switch in an environmentally-friendly way.
Components within the equipment can exceed the enclosure temperature by 1 K (1 °C). When the media temperature exceeds 80 °C, the user must ensure that the media temperature does not cause a thermal ignition risk on parts between the media and the switch enclosure. It is recommended that the maximum media temperature on the pressure switch is limited to 80 °C.
Isolation of the intrinsically safe circuit to ground and to the contact mounting screw has been verified through 500 VACrms dielectric strength testing, carried out in accordance with EN 60079-11:2012.
The maximum applicable cable length connected to the MP-E depends on cable capacity and inductivity. Cable capacitance and inductivity, together with the MP-E's Ci and Li, must meet the requirements of the applied zener barrier.

Declarations of Conformity

EU DECLARATION OF CONFORMITY

Company: Danfoss A/S, Refrigeration & Air Conditioning Controls

Product category: Pressure switches

Type designation(s): MPE

Conformity: Explosive or Protective Systems Intended for use in Potentially Explosive Atmospheres, Directive 2014/34/EU

Marking: Ex II 3G Ex ic IIB T6 Gc

Temperature range: Tamb. -20°C to +60°C

Test basis: EN IEC 60079-0:2018, EN 60079-11:2012

Date: 2021.08.12

Place of issue: Grodzisk Maz.

Issued by: Piotr Chylaszek (Atex Authorized Person)

Approved by: Lukasz Stasiowski (RD&E Manager)

UK DECLARATION OF CONFORMITY