Accessories for 3RM1 motor starter

The following accessories are available for the 3RM1 motor starter:

• 3-phase infeed system for the main circuit
• Device connectors for the control circuit
• Spare terminals for main and control circuits
  • Screw terminals
  • With push-in spring-type terminal
• Push-in lugs for wall mounting the motor starters
• Sealable cover as protection against unauthorized access

Three-phase infeed system (3RM19 three-phase busbar system)

Special three-phase busbar systems can be used to provide an easy, time-saving and safe means of feeding two or more 3RM1 motor starters with screw connection.

These busbars are available in three lengths, thus allowing 2, 3 or 5 motor starters (arranged side-by-side) to be connected at the same time. More than 5 devices can be connected by clamping the terminal lugs of a second busbar rotated by 180° (e.g., 6 devices with one 5-pole and one 2-pole busbar).

A single motor starter can be removed from the assembly without loosening the terminal screws of neighboring motor starters.

The maximum summation current must not exceed 25 A. Primary infeed is connected via a three-phase feeder terminal.

The three-phase busbars are finger-safe but empty connection tags must be fitted with covers.

3RM19 infeed system with three-phase feeder terminal: In the above example, two three-phase busbars (5-pole busbars) rotated through 180° allow up to 9 3RM1 motor starters to be connected. Contact with the unused connection tags in unoccupied positions is prevented safely by the covers.

Device connectors for the control circuit

The outlay for cabling between the devices is reduced using device connectors snapped onto a mounting rail, or screwed onto a level mounting panel (one device connector per motor starter).

Using the device connectors exclusively for feeding in the control supply voltage

By using device connectors, several motor starters can be jointly supplied with a control supply voltage of 24 V DC. This requires the control supply voltage to be applied to the A1 and A2 terminals of only one motor starter.

Up to ten motor starters can be connected with device connectors. The 24 V DC control supply voltage must be within the operating range of 0.9 to 1.1 for this purpose. If the full operating range of 0.8 to 1.25 is to be used, no more than five motor starters can be used.

If the motor starters are not to be connected together side-by-side, device daisy chain connectors must be used for the gaps.

When a motor starter is removed, the associated device connector must be replaced with a device daisy chain connector if the control supply voltage for motor starters located on the right is not to be interrupted.

The last motor starter in a row can be placed on a device termination connector. Flush termination of the configuration is thus possible.

In combination with the 3RM11 and 3RM13 Failsafe motor starters, the device connector can also be used for safety-related disconnection. For this application, groups of up to 5 Failsafe motor starters may be connected. The group must terminate with a device termination connector. The entire group shuts down safely by removing the control voltage supply at the first motor starter.

Device connectors snapped onto a standard mounting rail to allow the joint connection of the control supply voltage for 3RM1 motor starters or interfacing to 3SK1 safety relays

Using device connectors in conjunction with 3SK1 safety relays

Interconnection of several 3RM11 and 3RM13 fail-safe motor starters into a group can also be used for joint disconnection by a 3SK1 safety relay.

The motor starters are then disconnected by removal of the control supply voltage by means of the 3SK1 relay. For this reason, the voltage must not also be applied to the motor starters.

The motors can then also be shut down safely according to SIL 3 / PL e with the motor starters.

Up to five motor starters can be connected to one safety relay with device connectors. If the motor starters are not to be connected together side-by-side, device daisy chain connectors must be used for the gaps.

The last motor starter in a row must be placed on a device termination connector. This closes the circuits that were built up with the connectors.

For 3SK1 safety relays and associated device connectors see "Safety Technology" > "SIRIUS 3SK1 Safety Relays"

Usage restrictions for accessories

• The 3RM19 3-phase infeed system for the main circuit can only be used with 3RM1 motor starters with screw terminals in the main circuit.
• The device connectors are only suitable for 3RM1 motor starters with a control supply voltage of 24 V DC.