GIGAVAC HV Relay and High Voltage Relay Grounding requirements

<body> <h2><br> HIGH VOLTAGE RELAY GROUNDING REQUIREMENTS</h2> <p class="regularblack12">It is normal practice to ground the base of all high voltage relays for safety.</p> <p class="regularblack12"> For GIGAVAC <a href="../schematics/middle.htm" target="_parent">diaphragm style relays</a> (GIGAVAC G41, G43, G47, G81, etc), grounding is not necessary. This is because there is no ground plane inside the sealed switching chamber that an arc can go to during hot switching, and because the external distance to ground, combined with the added insulation of the coil, is greater than the breakdown voltage between contacts. These relays can be used in hot switching applications one either side of the load<span class="gray11"> (see Fig. 1)</span>.</p> <p align="center" class="regularblack12"><img src="../../../images/apps/fig1.gif" alt="HV Relays Grounding Requirements" width="272" height="168"><br> <span class="bluebold11">Fig. 1</span><span class="gray11">, for GIGAVAC diaphragm style relays, relay<br> can be on either side of load. Grounding of case is<br> not necessary but is recommended for safety.</span></p> <p align="left" class="regularblack12">For GIGAVAC <a href="../schematics/middle.htm" target="_parent">internal armature style relays</a> (GIGAVAC GH1, G8, G61, G50 etc.), the relay base must always be grounded <span class="gray11">(see Fig. 2)</span> unless the voltage across the contacts is less than the specified dielectric voltage breakdown between the coil and case. When hot switching voltages above the coil to case dielectric voltage rating, the relay MUST be on the ground side of the load <span class="gray11">(see Fig. 2)</span> and the case MUST be grounded. For hot switching voltages lower than the coil to case dielectric voltage rating, the relay can be on either side of the load <span class="gray11">(see Fig. 2 & 3)</span> and the case does not have to be grounded but is recommended to be grounded for safety.</p> <table width="640" border="0" align="center" cellpadding="0" cellspacing="0"> <tr> <td align="left" valign="top"><p align="center" class="regularblack12"><img src="../../../images/apps/fig2.gif" alt="Grounded HV Relay Base" width="256" height="168"><br> <span class="bluebold11">Fig. 2</span><span class="gray11">, for GIGAVAC internal armature relays, relay<br> should be ONLY on ground side of load unless voltage<br> is lower than the coil to case dielectric rating.<br> GROUNDING OF CASE IS REQUIRED. </span></p></td> <td align="right" valign="top"><p align="center" class="regularblack12"><img src="../../../images/apps/fig3.gif" alt="internal armature relays" width="262" height="168"><br> <span class="bluebold11">Fig. 3</span><span class="gray11">, for GIGAVAC internal armature relays, relay can<br> be on either side of load if voltage is less than the coil to<br> case dielectric rating. Grounding of case is not<br> necessary but is recommended for safety . </span><br> </p></td> </tr> </table> </body>