a) Alternating function
The alternating relay AVR100 switches both input contacts to a different output following each operating cycle.
Switchover is initiated when the inputs 1 and 2 respectively are voltage free, no matter if voltage was previously applied to one (base load operation) or to both inputs (peak load operation).
The relay remains in this control state until both inputs are again voltage free.

b) Fault response
The relay is also equipped with a fault response function.
If voltage is applied to the fault contact at the input terminal 7 assigned to pump 1 the alternating relay takes up a stable control state and continuously switches the input contact I (base load) to output 2 (peak load pump).
If voltage is applied to the input terminal 8 (fault pump 2) the input contact I (base load) is continuously switched to output 1 (base load pump).

c) Centralised alarm
The central alarm relay picks up as soon as voltage is applied to the inputs Fault pump 1 / Fault pump 2 / Fault 3 / 4 / 5. The fault inputs 6 and 7 operate with a delayed pick-up of approx. 30 s before enabling the central alarm relay.

Principal functions:

• Alternate following each operating cycle
• Base and peak load operation
• Switchover to reserve pump when fault occurs
• Two pick-up delayed fault inputs
• Compact design
• Simple to install with plug-in terminals