It is recommendedthat nomorethantwo of theseheaterpower suppliesbeplacedin series becauseof voltage insulation limitations. Any numberof thesepower suppliesshould bc able to berun in parallel with acommonloadaftermeetingcertainsystemrequirements. For either seriesor parallel operation, one power supply is designatedasthe masterunit with all other power supplies as slave units. The slave unit should be physically close to the masterandhavethe samechassisground. The masterpower supplyreferencereadout(J13-Eand J13-F) is connectedto the slavepower supply external reference ut (J13-P and J13-N). All slaveunits should berun in remote referenceandwill track the masterpower suppliesreference. An equal number of capacitorsshouldbeconnectedin all power suppliesfor current and voltage sharing. It is recommendedthat eachpower supplyhaveaseparatecontrol contactor opto coupler for the external tire command with the requirement that thesecontactsall openwithin 1msecof eachother. The separatecontactrequirementis alsoneededfor theexternal permit intlk. This is doneto avoid groundloopsat highervoltages. Local fire control is still independentof eachother. For seriesoperationthe outputsof the TWO power supplies areconnectedin series,positive of one to the negative of the second. A minimum of AWG #lO shouldbeusedfor all power leads. Page3 If seriesoperationover 800volts total (4OOV/powersupply) is desiredit is recommended that the 14mfd 250 volt capacitorin the crowbar trigger circuit bechangedto a 30 mfd 100 Vdc mylar capacitor. The circuit with the 14mfd is under compensatedand this may result in false crowbar trips over 800volt output. For parallel operationof the power suppliesit is bestto connectthem together at the load with ALL power supplies having approximately the sameoutput lead length. This will help in current sharingbetweenthepower supplies. Page4