Part 2

484 Plug-In Assembly ConfigurationType 1 Load - No Contact Protection RequiredNo contact protection is required if the load is resistive (noninductive) and contactcurrent lo is less than the minimum arcing current (la) of the relay contacts. For thehigh voltage actuator, since la = 400mA. no contact protection is required forresistive loads in which lo < 0.4A.To compute lo, use lo = VIRL (since L = 0 for a purely resistive circuit, Vc = 01.If lo < 400 mA, the load is type 1 and the internal snubber network can be removedif required. Note that lo is the peak current BEFORE the relay is opened, which shuntsRact so Ract is not used to calculate lo.I EXAMPLE - TYPE 1 LOADThis example shows a load which meets the criteria for a type 1 load. Apurely resistive load of 100 ohms is connected to a channel of the actuatorand a 30 volt DC power supply is used as the source voltage.To determine that this a type 1 load, compute lo = V/RL = 301100 =300 mA. For a resistive load, since L = 0, Vc = lo fi - 0. Sincelo = 300 mA is less than la = 400 mA, the load meets the criteria fortype 1 and no contact protection is required. However. leave the snubbernetwork in unless absolutely necessary to remove it.SNUBBER CAN BEREMOVED IF REQUIREDLMKU' '- ' --lit--.VDC=JOV PEAK3: RL=lOOnvc=a3497-OPC-152TYPE 1 LOAD CONNECTED TO THE ACTUATORArtisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com