Question 1

What is paralleling switchgear?

Accepted Answer

Paralleling switchgear is the protection, control, and communications equipment required to operate two or more generators (or a generator and the utility) in parallel on the same bus. It handles dead-bus closing, synchronization, real and reactive load sharing, load shedding under fault, and orderly transfer between sources. It is the standard solution for multi-engine generator plants in healthcare, data centers, utilities, water and wastewater, and industrial facilities.

Question 2

What is the difference between paralleling switchgear and a transfer switch?

Accepted Answer

A transfer switch moves load between one source and another in an open or closed transition: one source at a time, no overlap (or a brief synchronized overlap for closed transition). Paralleling switchgear holds multiple sources on the same bus, sharing load. Transfer switches are right for small standby systems with one generator. Paralleling switchgear is required when two or more generators must run together, when closed-transition transfer is required for prime-power or peak-shaving applications, or when the facility runs alongside the utility.

Question 3

Do you support medium voltage paralleling or only low voltage?

Accepted Answer

Both. We engineer low voltage paralleling switchgear (208V through 600V, UL 1558) and medium voltage paralleling switchgear (4.16kV through 15kV class, IEEE C37.20.2 metal-clad). Medium voltage is common for larger generator plants where the LV bus would otherwise be impractical from a fault-current or copper standpoint.

Question 4

Can you retrofit existing paralleling switchgear instead of replacing it?

Accepted Answer

Yes, and for most facilities with 1990s or 2000s-era paralleling gear, retrofit is the faster and lower-cost path. The structural switchgear and breakers are often still serviceable; the obsolete paralleling controller, sync check relay, and metering are what have actually aged out. We retrofit under IEEE C37.59 design verification, with phased execution that keeps the plant powered throughout. New paralleling controllers, modern protective relays, closed-transition transfer (where retrofit-compatible), and a documented sequence of operations.

Question 5

Do you work with non-Caterpillar generators?

Accepted Answer

Yes. We are vendor-neutral. We integrate with Caterpillar, Cummins, MTU, Kohler, Generac, Mitsubishi, and other generator OEMs through open communication protocols (Modbus to most ECUs, manufacturer-specific protocols where required). The paralleling switchgear is not tied to one generator brand.

Question 6

How does closed-transition transfer work, and when do we need it?

Accepted Answer

Closed transition briefly parallels the utility and the generator bus during transfer, so the load never sees a blink. Required for processes that cannot tolerate any interruption, common in data centers, hospitals, and certain industrial applications. Also used in peak shaving and base-load operation, where generators run continuously alongside utility. Requires a sync check and utility coordination, both of which are part of the standard paralleling switchgear scope.

Question 7

How long does a paralleling switchgear project take?

Accepted Answer

For new construction, typically 30 to 50 weeks from engineering through commissioning, depending on generator availability and switchgear configuration. For a retrofit of existing paralleling switchgear, typically 20 to 30 weeks. Both are substantially faster than the 52 to 100 week lead times currently quoted by the major OEMs for new equipment.

Question 8

Will the paralleling switchgear lock us into your service?

Accepted Answer

No. Every system is vendor-neutral by design. Open protocols, documented data models, standard component selection, and a complete documentation package. Your in-house team can maintain it, any qualified third party can maintain it, or we can maintain it. The choice stays with the facility for the life of the equipment.

Paralleling switchgear, Engineered to your plant, not pulled from a catalog

Engineered to the plant, not configured from a menu.

Standby, prime, peak shaving, or base load.

What actually happens when the lights blink.

Build new, or modernize what you already have.

Build new

Retrofit existing

The technical envelope.

Where we fit alongside the major paralleling vendors.

From plant review to commissioning in four steps.

Plant review

Engineering package

Factory build or in-place retrofit

Commission, train, monitor

What a finished paralleling switchgear plant looks like.

Built for plants that have to stay up.

Healthcare

Data Centers

Utilities & Generation

Water & Wastewater

Deeper reading and adjacent work.

Low voltage switchgear

Arc resistant switchgear

Custom switchgear

Paralleling switchgear retrofit

What is paralleling switchgear?

Switchgear retrofit guide

Answers from our engineering team.

Talk to a Power Systems Engineer

Tell us about your paralleling plant