UPS Recommendation for Agilent MSD

Version 1

    UPS Systems - For use on GC/MS Systems

    Agilent Technologies does not recommend the use of a UPS or other isolation devices to supply power to a GC, GC/MS or ICP-MS system. These instruments present a highly varying load to these isolation devices. The oven of a GC, for example, is controlled by either turning power on or off each cycle of the line voltage. This creates a varying load condition on the UPS or isolation deveice of approximately 100 Watts when the oven heater is off and 2000 Watts when the oven heater is on. Since the heater may be powered off for one cycle and powered on for the next cycle of the line voltage, this creates a highly repetitive level of load variation. Many isolation devices require several line cycles to recover from high load variations. These isolation devices do not have sufficient damping capacity to correct for the magnitude and frequency of load variation created by the GC, GC/MS and ICP-MS instrumentation.


    Some isolation devices create undamped oscillations when subjected to repeated cycle-by-cycle, high-level load variations. These units will actually create very high levels of transient voltage supplied to the load. These undamped oscillations often exceed the specifications for the Agilent systems or the isolation device, or both. Additionally, the high variation in load is created at a 50/60 Hz rate. Use of UPS or other isolation devices utilizing Ferro-resonant transformers, regulators, or supplies is specifically NOT RECOMMENDED since the large load variations at the resonant frequency of the transformer may cause the transformer to operate unpredictably.


    This operation often causes the Ferro-resonant transformer to overheat or malfunction.


    Please contact the manufacturer of the UPS or other isolation device if you wish to use these to supply power to Agilent Technologies GC,GC-MS, or ICP-MS system. Inform the isolation device manufacturer of the varying cycle-by-cycle load behaviorof the Agilent system to obtain a recommendation from the manufacturer for t he proper size, capacity and type of UPS or other isolation devices.