17 Jun 2020
Four years ago Mechan Controls launched its innovative, modular EM1 safety relay with the aim of offering an 'intelligently simple' safety relay that was expandable and, more importantly, non-programmable. After thousands of units had been sold into a variety of applications and industries, the decision was taken to make further improvements to the existing design.
The main objective of the EM1 was to eliminate fault masking, without the need for programming, and this was achieved using the ESM extender module. In order to achieve CAT4, SIL3, PL-e, each dual-channel safety device must be connected to its own set of safety inputs. However, this method meant the old EM1 required a considerable amount of space compared with a programmable safety relay.
The second thing Mechan Controls addressed in the new design was the limitation on the number of ESM extender modules that could be added. The previous version supports a maximum of 12 modules; this was due to the power limitations, as each extender module drew power from the EM1 master control unit.
The new EM1 is now one-third of the size and features a host of new features and technological advances over its predecessor. Mechan Controls' experienced hardware and software engineers have used the latest design methods to reduce the size, double the number of extender modules that can be added and improve the diagnostic features.
Key features include:
Each EM1 and ESM includes two cross-monitored safety inputs that are designed to accept any dual-channel, volt-free safety device. These can include:
It is strongly recommended that users connect one dual-channel safety device per set of safety inputs to achieve CAT4, SIL3, PL-e.
The new EM1 design features advanced software via the use of microcontrollers. This method of design meant Mechan Controls has been able to include more 'intelligent diagnostic checks. These include: