An industrial UPS proposal can become invalid without any change to the UPS itself. The trigger is often a change in what the customer expects the system to protect. In an anonymized GDF Technologies proposal, the initial basis was a 480 V facility, an Xtreme Power Conversion X90-1S rated at 50 kW, and an external battery cabinet. The customer later considered placing substantially more plant load on the UPS. GDF stopped the requote until the real load and protection priorities could be confirmed.
That pause protected the customer from a larger but still potentially inadequate selection. It also protected both parties from releasing a custom battery cabinet against an unstable design basis. The retained field record does not contain a final installed model, final battery quantity, measured load, runtime result or commissioning outcome. The useful result is the qualification method.
Operating context
The work concerned a new 480 V industrial installation. The first concept used the XPC X90-1S at 50 kW with external batteries. XPC currently describes the X90-1S as an online double-conversion three-phase UPS with 480 V input and output, offered in 50 kW and 70 kW configurations. Its integrated cabinet includes the power module, internal batteries and maintenance bypass, while external battery options address longer autonomy requirements [1].
Those published characteristics establish a credible product family and voltage class. They do not establish that 50 kW, 70 kW or another size is suitable for an unidentified plant load. A UPS rating is only one part of the selection. The protected load schedule, load behaviour, autonomy objective, bypass arrangement, fault-current context and growth basis must agree with it.
Figure 1. Commercial progress stopped when the engineering basis changed. Graphic by GDF Technologies from the anonymized field record [2].
The scope change that stopped the requote
The customer suggested protecting much more of the facility than the original concept covered. The retained correspondence indicates that even a roughly 140 kW alternative might not have resolved the requirement. That figure was an exploratory discussion point, not a selected rating and not a verified site demand. GDF did not convert it into a published solution claim.
The correct response was to ask what equipment had to remain online and what its actual operating load was. Nameplate totals alone would not answer that question. Motors, drives, rectifiers, transformers and process equipment can impose inrush, harmonics, regeneration or operating-state changes that a simple kW sum misses. Simultaneous operation also matters. A production line may have loads that are never active together, while a restart sequence may create a temporary peak above the steady value.
The protection boundary had to be redrawn before the product could be resized:
| Qualification input | Why it matters | Acceptable evidence |
|---|---|---|
| Critical load list | Defines what must remain on UPS power | Approved single-line diagram, panel schedule and equipment list |
| Real demand | Establishes kW and kVA in normal and credible peak states | Logged meter data or coordinated field measurements |
| Power factor and waveform | Prevents kW-only selection | Meter record plus equipment information |
| Inrush and overload | Tests transient compatibility | OEM load data, sequence information and measured events where available |
| Required autonomy | Determines battery energy at the qualified load | Operating requirement with start and end conditions |
| Bypass and source arrangement | Determines maintainability and fault exposure | Electrical design and site operating procedure |
| Growth allowance | Separates committed future load from a vague contingency | Approved project forecast |
Why a larger UPS was not a complete answer
Increasing the UPS rating can create new site requirements. Input current, upstream protection, conductors, heat rejection, floor loading, clearances, bypass capacity and generator interaction may all change. External battery capacity and recharge time can also change. The physical route for cabinets and equipment must remain workable.
More importantly, an oversized rating does not correct a poorly defined load. If non-critical process equipment is added without priority rules, the UPS may carry avoidable load while the truly critical functions receive less runtime. If motor starting is ignored, the selected system may appear adequate in steady operation but fail to support the required transition. If the generator and UPS are not considered together, recovery after an outage may be unstable.
The design basis therefore had to answer two separate questions:
- Which loads require uninterrupted power?
- What electrical and autonomy duty will those loads impose?
Only then can the engineer select a power rating, redundancy basis and battery configuration.
Figure 2. A changed load returns the proposal to qualification. Graphic by GDF Technologies [2].
Commercial control was part of the engineering work
The field record identified a custom battery cabinet as non-cancellable. That condition raised the consequence of an early release. A purchase order based on the original load could have locked in an enclosure, battery arrangement or lead time before the final duty was understood.
GDF kept the technical and commercial records aligned. The quote could not safely advance until the same assumptions appeared in the load schedule, runtime basis, equipment selection and supplier order. Where information remained open, it had to be stated as an assumption or exclusion rather than absorbed into a rounded allowance.
| Release gate | Required record | Stop condition |
|---|---|---|
| Load boundary | Approved list of included and excluded loads | Customer is still considering additional plant loads |
| Capacity | Calculated kW and kVA with transient review | Demand is based only on an estimate or nameplate sum |
| Runtime | Defined load, duration, battery endpoint and ageing basis | Customer asks for “more runtime” without a duty point |
| Electrical integration | Confirmed voltage, phase, source, protection and bypass | Single-line diagram or site conditions remain unresolved |
| Custom equipment | Approved dimensions, interfaces and commercial terms | Non-cancellable item depends on an unsettled design input |
This is not administrative delay. It is a procurement risk control. The most expensive time to discover an assumption is after custom equipment has entered production.
Evidence boundary
The retained material supports only a proposal-stage account. It confirms the 480 V context, the 50 kW X90-1S concept with external batteries, the later expansion of the protected-load idea and GDF’s decision to stop the requote pending real load information. It does not support claims about installation, energy savings, reliability improvement or successful commissioning.
Figure 3. The publication boundary follows the retained evidence. Graphic by GDF Technologies [2].
The boundary prevents an unfinished design from being presented as an installed success. The documented engineering decision is the recognition that the original selection basis no longer applied.
A practical qualification brief
For a similar 480 V industrial requirement, GDF would seek the following before final release:
- single-line diagram and source information;
- panel and load schedules identifying the exact protected boundary;
- measured kW, kVA, power factor and credible peak states;
- motor, drive, transformer and rectifier characteristics;
- required autonomy with a defined load and end condition;
- normal, bypass, maintenance and emergency operating states;
- generator data where the UPS will operate from standby generation;
- room temperature, ventilation, access, floor loading and cable routes;
- future load that has an approved date and quantity;
- commissioning, acceptance and documentation requirements.
The output should be a traceable design basis, not a single headline rating. If the load changes again, the affected calculations and commercial records can then be identified and revised.
GDF Technologies support
GDF Technologies can qualify three-phase UPS requirements, review load data, coordinate runtime calculations and structure the quote around explicit assumptions and release gates. See GDF Technologies’ Xtreme Power Conversion services for service context. Final equipment selection requires site-specific engineering and current manufacturer documentation.
References
- Xtreme Power Conversion, X90-1S product page, accessed July 12, 2026.
- GDF Technologies, GDF Field Case Library: Engineering and Quoting Patterns, anonymized internal record, 2026.
GDF Technologies services every UPS brand covered here, across Canada. See our preventive UPS maintenance plans or call (514) 252-8324 for on site support.