The HPA Series performs AC withstand testing on electrical apparatus including switchgear, motors/generators, bushings, breakers, bus duct, etc. Many models are corona free (<10 pc) for performing elevated voltage partial discharge and tan delta or power factor testing.

HVI offers models from 3 kVA – 40 kVA with voltage ratings from 3 kV AC – 300 kV AC. Most models are designed for use in a stationary factory environment. However, some are portable for field or mobile factory use. HVI also produces other product lines of high power field use AC hipots, like the FPA Series.

Various control packages are available, from simple manual controls to fully programmable logic control (PLC) options.

HVI offers a full line of AC Dielectric Test Sets up to 300 kV in voltage and 40 kVA in power.
Conventional test sets are available as well as specialty models, like several designed specifically for motor winding testing. They are all rugged in design, with either oil filled steel or fiberglass high voltage sections and well designed, attractive controllers with all the features needed. Custom models are also available upon request. If lower power models are sufficient for your application, then consider our standard, portable PFT Series of 1 kVA and 3 kVA AC Hipots, available from 10 kV – 100 kV.

Also available are just the high voltage sections used within the test sets described here, like our 50 kV @ 10 kVA HV tank for testing rubber gloves, aerial lift liners, hot sticks, and other similar loads.

Selecting an AC Dielectric Test Set
AC high voltage testing requires higher power/current ratings than when DC testing the same load. There are several parameters that must be considered when selecting an AC test set, the most important one being the capacitance of the load, which dictates the power required from the test set. Following are several considerations when specifying a test set:
Voltage Output
Select a test set with perhaps 20 – 25% more voltage than presently needed for possible future increases in testing standards or changes in application. However, the output current of the test set is based on the kVA rating at full voltage. Any increase
in the output voltage rating for the same kVA rated test set will proportionately decrease the current rating.
Power/Current Rating
When AC testing, most loads appear capacitive. To apply high voltage AC at 50/60 Hz to capacitive loads requires higher power and current ratings from the test set than typical portable AC hipots can supply. A test set rated for 10 – 20 kVA may
be needed depending on the load to be tested. The capacitance of the load must be known in order to calculate the required current at the required voltage. Don’t undersize the set: select a test set with at least 20 – 25% extra power than believed
needed. To determine the current needed from the test set, the following formula should be used:
A = 2πfCV
A = Test current required in Amps (A) f = Test frequency in Hertz (Hz)
C = Load capacitance in Farads (F) V = Test voltage in volts (V)
Another way to determine the current needed at the required test voltage is to apply a lower voltage to the load and measure the current. The current required at the actual higher test voltage should be fairly lin-ear. For example: if your load draws 10 mA @ 5 kV it will draw approximately 100 mA @ 50 kV. Remem-ber, an AC test set is a constant current device. The maximum output current is the same at any output voltage.
Duty Cycle
Most AC hipoting is performed for 60 seconds at a time. However, production testing may require consecutive tests over many hours. Most HVI AC test sets are duty rated for 50%, meaning full power can be delivered for one hour on followed by one hour off. The continuous duty rating is approximately 80% of full rating. Consult product specifications for details.
Partial Discharge Requirements
Many HVI AC test sets are rated for <10pc of partial discharge at full voltage, but not all. Generally, steel tank bushing output models are <10pc while models with fiberglass HV sections and/or a cable output are not. Consult factory.

High Voltage Section Configurations
Except for the lowest 5 kVA, 10 kVA, and 20 kVA models that contain the HV section within the control cabinet, all models have a separate HV section. There are two HV section designs, a steel tank with a bushing output and a fiberglass cylinder with a toroid/spinning output. HVI can supply a one piece design on several of the lower voltage models, like the 10 kV model pictured in this brochure. A steel tank with a cable output on models rated up to 50 kV is possible on a custom basis. No HV output cable is provided on bushing and spinning output models. See the pictures in this brochure for examples of the various layout configurations.

Three Standard Control Packages – Variations Available On a Custom Basis
Fig. C1
Simplified Controls w/manual output voltage control – up to 5 kVA
Voltage meter: two range
Current meter: three range
Main Power breaker/indicating light
HV On/Off
Output Adjust control knob
Variable Overload w/reset

Fig. C2
Simplified Controls w/motorized output voltage control – up to 10 kVA
Voltage meter: two range
Current meter: three range
Control Power breaker/indicating light
HV On/Off
Voltage Raise/Lower control
Fixed voltage rate-of- rise
Variable Overload w/reset
Emergency Off button

Fig. C3
Automatic Controls & Digital Metering – any kVA
Voltage meter: digital 3.5 digits
Current meter: digital 3.5 digits
Control Power breaker
HV On/Off
Output Mode Manual/Auto
Output Voltage Raise/Lower control
Four fixed volts/second rates-of-rise
10 – 100 seconds, consult factory
Test Dwell timer
Variable Overload w/reset
Emergency Off button

OPTIONS:
PLC Interface: Includes 0-10Vdc signal outputs for voltage and current monitoring, 0-10Vdc signal inputs for voltage and current set points, and normally open contacts for control of power on/off, remote enabled, overload, voltage raise & lower, and other control features. Consult factory for additional controller packages.