Figure 1 above shows an LP-2 and a RT-1 supplying power for a high surge current, 2 stage electric lock. The first stage of a typical vertical bar electric lock draws 16 Amps for about a ½ of second to unlock the door. After the initial surge from the first stage, the second stage holding current is about 300ma. Because the LP-2’s current is limited to 3 Amps, you must use either a standby battery or capacitor to supply the balance of the high current surge. After the surge the LP-2 will quickly recharge the storage device. The capacitor is used when no standby power is desired. The Electrolytic Capacitors can be obtained from www.digikey.com or www.mouser.com
The heavy contacts of the RT-1 (see *RT-1HD note below) are used switch the high current locally to the door locks. Only a small control current goes back the access control panel.
The SN-1 is placed across the door lock to suppress interface and protect the LP-2 from the very high spikes generated from the electric lock.
Refer to Technical Sales Bulletins LP-2, RT-1, RT-1HD and SN-1 for more information.
*RT-1HD Note: Our RT-1HD 12v or 24v Heavy Duty Relay has 40A rated form C contacts. We recommend this over the RT-1 15A relay used above for good long term reliability.