UPS Maintenance Bypass Switches

An external UPS maintenance bypass switch provides additional maintenance and service facilities to a uninterruptible power supply installation. Also referred to as a bypass switch or wraparound panel, the device allows the UPS to be isolated safely for maintenance work or removal without interruptible to the load. UPS maintenance bypasses from Server Room Environments include standard products for wall or rack mounting and bespoke bypass solutions made to order with options for parallel UPS installations and Castell interlocks.

UPS Bypass Options

A UPS maintenance bypass switch must be matched correctly to the uninterruptible power supply it is to be installed with. The principle considerations include:

  • Rating: the bypass must be rated to be equal to (or less than) the total output rating of the UPS in kVA or Amps. For a 2kVA UPS this means selecting UPS that can supply 2kVA or less.
  • Input and Output Supplies: the bypass switch must match the UPS installation mains power supply and load phases. Most single-phase UPS are configured 1/1 where the input and output is single phase but a 3/1 configuration denotes a three phase input and single phase output. A three phase input and output is referred to as a 3/3 installation.
  • Mains Power and Load Connections: Most installations up to 3kVA will have plug and play connections and make use of IEC320 C13 and C14 cables. Hardwired inputs and outputs are an option for UPS maintenance bypass switches 3kVA and below. Above 3kVA installations typically require hardwired connections and therefore installation by a suitable qualified electrician or electrical contractor.

Custom Bypass Panels and Switchboard Designs

If a project requires a custom bypass panel or switch this can be designed and once approved manufacture within 10-15 working days. Custom options include interlocking (Castell), volt-free signal contacts for remote monitoring, built-in panel meters and LCD panels, a local power sockets for service engineer use, and parallel UPS operation. Bypasses may also be supplied with additional protection including lighting and surge protection. Custom panels can also be painted to virtually any specific data centre colour schemes.