Automatic Voltage Regulators

Will the VRP voltage regulator correct a distorted waveform?

No. Current to the load passes through the phase conductor. Regulation current is taken from the incoming phase. The voltage correction is up to +-26%. Only a dual conversion voltage regulator would be able to provide waveform correction.

Can the three-phase VRP receive power from a delta source?

No, VRP must receive power from a wye source with three phase conductors plus neutral.

Does VRP have a bypass switch?

Yes, VRP has an automatic bypass switch.

What does the automatic bypass switch do?

If VRP’s control PCB fails, it will automatically switch to bypass, allowing unregulated voltage to power the connected load. The surge filter board would continue to be in circuit, though. This feature prevents an unscheduled shutdown of the connected equipment.In machinery models provided with high- & low-voltage cut-off, raw power will only go into the connected equipment if its voltage is within the cut-off range.

What happens if the VRP control circuit board fails?

All LEDs will switch off. The load current will pass unregulated to the connected load. In some cases, the VRP main circuit breaker needs resetting. Contact TSi Power for an RMA or replacement control circuit board.

Is VRP available with under- and over-voltage cut off?

All standard VRP’s- machinery models are supplied with built-in OVP/UVP cut offs.

Isolation Line Conditioners

What is leakage current to ground and why is it possibly harmful?

Ground leakage current occurs when wire insulation is damaged or becomes frayed with age. Then, small amounts of a current can flow into the grounded metal cabinet or chassis. The maximum allowed ground leakage current is a few milliamps (thousands of an amp). A GFCI (ground fault circuit interrupter) can be used to detect higher-than-normal ground leakage current and turn off the circuit, which is the reason in many countries for mandatory GFCI-protection of AC sockets near earth ground, bathtubs or showers. By detecting the current through a person’s body into the ground and then tripping the circuit, GFCI can prevent electrocution when a person accidentally comes in contact with a live AC source.Under UL 60950-1 (the standard for safety of information technology equipment including electrical business equipment), the maximum allowed ground leakage current per each computer or office equipment is a few milliamps. However, when there are hundreds computers, IT equipment and electrical business equipment in each floor of a high-rise building, each floor can produce a combined leakage current of one or two amps. When there are 10, 20 or 30 floors, total leakage current for the building can exceed 10, 20 or even 30 amps.The presence of constant leakage current violates various safety codes, which allow momentary current through earth ground wire only for short-circuit protection and surge current when TVSS (transient voltage suppression system) is activated due to transients or lightning strikes.Another consideration is differences in ground potential between floors. For example, the earth ground wire on the 20th floor may read several volts higher than the earth ground wire voltage on the ground floor. This may cause equipment malfunction and/or damage when data communication wires are connected between ground floor equipment and equipment at upper floors.Therefore, minimizing ground leakage current in a large building is very important for ensuring personnel safety, equipment functionality and equipment protection from stray voltages and ground loop currents.

What are the key benefits provided by ILc ?

By using a low leakage isolation transformer, typical ground leakage current can be reduced to about 100 micro amps (which is typical) even if the ILc is powering a load with high-leakage current of several milliamps or even more. Therefore, using an ILc can reduce ground leakage current by 10:1 or even 100:1.If multiple ILc units are used to power all the “leaky” IT equipment inside a high-rise building, then reducing ground leakage current by more than 90% will solve most of the problems associated with ground potential differences between floors. An ILc is designated as a “Separately Derived Power Source” under United States. National Electrical Code 250-5D and recommended by US federal government’s FIPS Publication 94 for elimination of problems caused by presence of neutral voltage, noise and transient voltages on the neutral line (common mode noise and transients).

Custom Solutions

Does TSi Power develop custom products for low-volume requirements?

Yes. We offer both custom solutions and customizable products for a variety of situations. Please fill out the Customer Requirements Form and contact us to discuss your needs Customer Requirements Form.

Does TSi Power require non-recurring engineering charges (NRE)?

It depends on the project and the size of the potential order. Because most of the custom products that we quote use parts from our standard toolbox of designs, we typically do not need to charge for NRE. TSi Power will quote NRE as a separate item if the project requires an extensive commitment of internal or external resources, or third party inspection & testing and listing/marking services.

Surge Protection Devices (SPDs)

What are the various types of surge protection devices and where should they be used?

UL 1449, 3rd edition (effective September, 2009) provides following surge protector classifications:

Permanently Connected (PC)

Direct Plug-In (DPI)

Cord Connected (CC)

Type 1 – Permanently connected (PC) between service transformer and line side

Type 2 – Permanently connected on load side of service disconnect

Type 3 – Point of Use: minimum 10 meters from service panel

Type 4 – Component assemblies for SPD (surge protection device) or other non-SPD applications such as appliances

Type 5 – Discrete components for SPD or other non-SPD applications such as appliances