Free ESIP Practice Questions

Question 1

A customer needs critical loads restored after the site has been completely shut down, with neither the utility nor a generator available. The proposed inverter can form an island, and its approved isolation device has passed an outage-transfer test while the inverter was already operating. Battery energy and load-starting capability are adequate. What additional demonstration establishes that the system meets the customer's startup requirement?

Accepted Answer

It starts the required controls and energizes a dead AC bus using battery power.

Answer

It maintains island voltage and frequency when a large load is added to an energized bus.

Answer

It resynchronizes with the utility after grid power returns.

Answer

It preserves the specified outage reserve while performing normal tariff-based dispatch.

Question 2

The short-circuit current rating (SCCR) label on an ESS control cabinet states 5 kA, or 22 kA when protected by a specified fuse. The installed fuse meets every condition on that label and has a 100 kA interrupting rating. Available fault current at the cabinet is 10 kA. All ratings apply to the actual circuit voltage and AC/DC system type. Which conclusion is correct for the cabinet's SCCR check?

Accepted Answer

It passes because the specified combination provides a 22 kA cabinet rating.

Answer

It fails because the 5 kA cabinet rating is below the 10 kA fault current.

Answer

It passes because the fuse gives the cabinet a 100 kA short-circuit current rating.

Answer

It fails unless the fuse reduces the prospective available fault current below 5 kA.

Question 3

A commercial tariff bills demand using the single highest 15-minute import interval in each calendar month, with no ratchet or time-of-use demand adjustment. An ESS enters service halfway through the month, after an unshaved peak has been recorded. Every remaining interval will be below that peak even without storage, yet the financial model credits additional demand-charge savings for shaving each remaining day's peak. How should the current-month estimate change?

Accepted Answer

Remove the current month's demand savings and assess energy-charge savings separately.

Answer

Keep daily peak-shaving savings because their average determines billed demand.

Answer

Prorate demand savings for the fraction of the month the ESS operates.

Answer

Remove both demand and energy savings because the earlier demand peak remains on record.

Question 4

A service panel has a 225 A bus and a 200 A main breaker. One source feeder combines PV and storage output, with a maximum simultaneous continuous output of 54 A. It connects at the opposite end of the bus from the main and qualifies for the 2020 NEC 705.12(B)(3)(2) busbar method. All other conductor, protection, and load checks are satisfied. Does this interconnection require a change to the bus or main breaker?

Accepted Answer

No; the existing bus and main allow up to 56 A of continuous source output.

Answer

Yes; more than 40 A of continuous source output requires a smaller main.

Answer

Yes; the 200 A main plus the 54 A source exceeds the 225 A bus.

Answer

No; the existing bus and main allow another 16 A beyond the proposed source output.

Question 5

Load-dependent current is detected on the equipment grounding path of a backup subpanel. Its feeder includes L1, L2, neutral, and an equipment grounding conductor (EGC). The approved design retains the service-neutral connection in both grid and backup modes; the backup source is not separately derived, and the subpanel is in the same building. Inspection finds its neutral-to-enclosure strap still installed. All relevant sources are now isolated and absence of voltage verified. What correction addresses the cause?

Accepted Answer

Remove the neutral strap; retain the EGC connection and enclosure equipment bond.

Answer

Retain the strap and add a grounding electrode at the subpanel.

Answer

Retain the strap and disconnect the feeder EGC to eliminate the parallel return path.

Answer

Retain the strap and upsize the neutral so it carries more of the normal return current.

Question 6

Two identical battery strings feed a common power conversion system through separate fixed branch cables. String A repeatedly supplies less current than string B at matched state of charge, temperature, and voltage. During an approved, isolated diagnostic procedure, the complete strings, including their battery management systems, exchange positions while the branch wiring stays in place. Repeating the operating test shows that the lower current remains at the original branch position. Which fault hypothesis should lead the next investigation?

Accepted Answer

Excess resistance in that position's fixed cables or terminations.

Answer

Reduced cell capacity in the original string A.

Answer

A discharge-current limit stored in string A's battery management system.

Answer

The common power conversion system reaching its total discharge-power limit.

Question 7

A proposed battery substitution has the same nominal voltage and mating connectors as the original model. The replacement is listed to UL 1973 and has a favorable UL 9540A fire-test report; the existing inverter is listed to UL 1741. However, the complete ESS listing identifies only the original battery model. What evidence would close this gap in the substitution review?

Accepted Answer

An updated ESS listing identifying the exact replacement battery and existing inverter combination.

Answer

A successful field polarity and charge-discharge test documented in the commissioning record.

Answer

A revised one-line confirming unchanged voltage, conductor ampacity, disconnect ratings, and overcurrent protection.

Answer

A compatibility letter citing the separate component listings and their matching nominal DC voltages.

Question 8

Commissioning an LFP battery expansion requires voltage and state of charge (SOC) to be matched before the additional string is connected in parallel. The existing and new strings have the approved model and firmware. Their resting terminal voltages match within the required tolerance, but neither has a validated SOC estimate. The installer records both acceptance criteria as satisfied. How should the commissioning lead assess that entry?

Accepted Answer

Verify SOC separately; LFP's flat voltage region can conceal charge-state differences despite matching voltages.

Answer

Accept it; identical battery models have the same relationship between resting voltage and SOC.

Answer

Accept after a longer rest; removing transient voltage effects makes resting voltage a precise SOC check.

Answer

Use a higher-resolution voltmeter; closer voltage agreement establishes that the separate SOC criterion is satisfied.

Question 9

For a 90-minute outage, an ESS must supply a constant 6.0 kW critical load. Its current battery capacity is 40.0 kWh DC, and state of charge may fall from 80% to no lower than the customer's 50% reserve. Both percentages refer to that capacity. Discharge-path efficiency is 90%, and the inverter supplies up to 9.0 kW AC continuously. There is no recharging, auxiliary consumption, startup surge, or other limit. What is the largest constant noncritical AC load that may remain connected throughout the outage?

Accepted Answer

1.20 kW

Answer

0.48 kW

Answer

2.00 kW

Answer

3.00 kW

Question 10

Procurement selects an IP67 ESS enclosure for an outdoor area cleaned with powerful water jets, reasoning that temporary-immersion protection must cover the cleaning exposure. The manufacturer has supplied neither a water-jet qualification nor cleaning permission. Which evidence addresses the proposed exposure?

Accepted Answer

Powerful-water-jet evidence to IP66 and manufacturer permission for the proposed cleaning conditions.

Answer

IP68 immersion evidence, since a higher second digit establishes all lower water-exposure ratings.

Answer

IP65 qualification and a cleaning procedure prohibiting immersion, because that combination covers water-jet exposure.

Answer

A conversion chart treating the IP67 label as equivalent to a NEMA 4X enclosure rating.

Free ESIP Practice Questions

Domain 1: Development 15% of exam

Question 1

Question 2

Question 3

Domain 2: Design 25% of exam

Question 4

Question 5

Question 6

Domain 3: Installation 30% of exam

Question 7

Question 8

Domain 4: Commissioning 17% of exam

Question 9

Domain 5: Operations, Maintenance, and Decommissioning 13% of exam

Question 10

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