The 7VE61 and 7VE63 paralleling devices of the SIPROTEC 4 family are multifunctional compact units used for paralleling power systems and generators.Their technical design ensures highly reliable paralleling due to their 1-channel or 2-channel measurement method and their hardware design. This is supported by numerous monitoring functions. The units automatically detect the operating conditions. The response to these conditions depends on settings. In synchronous network switching mode, the frequency difference is measured with great accuracy. If the frequency difference is almost zero for a long enough time, the networks are already synchronous and a larger making angle is permissible.If the conditions are asynchronous, as is the case when synchronizing generators, the generator speed is automatically matched to the system frequency and the generator voltage to the system voltage. The connection is then made at the synchronous point, allowing for circuit-breaker make-time.The 7VE61 paralleling device is a 1-channel unit (paralleling function + synchro-check) for use with small to medium-size generators and power systems. It is more reliable than 1-channel paralleling devices. It can also be used for synchro-check, with parallel operation of three synchronization points.For larger generators and power systems withhigh reliability requirements, the 2-channel 7VE63 is recommended. Two independent methods decide on the connection conditions. The unit also has the full control functions of the SIPROTEC 4 family.Voltage and frequency functions including voltage vector jump (??) are optionally available for protection or network decoupling applications.The integrated programmable logic functions (continuous function chart CFC) offer the user a high flexibility so that adjustments can easily be made to the varying requirements on the basis of special system conditions.The flexible communication interfaces are open to modern communication architectures with control systems.