Predictika · On-load tap-changer orders

An AI sales agent's on-load tap-changer order, checked before it goes out

An AI sales agent prepares an order for a VACUTAP VV on-load tap-changer with a type, a voltage class, a through-current, a step voltage, a number of operating positions, an insulating fluid, an oil conservator and the figures it states for filling quantity and weight. Before it goes out, the agent sends it to Predictika, which checks it against a declarative model of the technical data Maschinenfabrik Reinhausen publishes and returns a verdict, every reason and the figures it computed.

Scope: VACUTAP VV on-load tap-changers (VV III 250, 400 and 600; VV I 401): voltage class, current, step voltage, operating positions, ratings, fluid, conservator and ambient limits, stated figures. See everything this validator covers

This validator models orders for the VACUTAP VV family (the three-phase VV III in 250, 400 and 600 A ratings and the single-phase VV I 401), not just the scenarios shown below.

  • Type and voltage class — VV III is listed at 40, 76, 123 and 145 kV and VV I at 76 and 145 kV; the through-current must not exceed the rating of the type (250, 400, 600 and 400 A) and the step voltage must not exceed 2,000 V. For some types the listed maximum step voltage falls with the current, so higher values go to a person to check against the step capacity diagram.
  • Operating positions and ratings — at most 12 positions without a change-over selector and 23 with one; rated short-time current 6 kA for 3 s, peak withstand 15 kA, frequency 50 to 60 Hz, and the lightning impulse withstand across the tap winding for the voltage class.
  • Fluid, conservator and ambient limits — mineral and recycled mineral oils are listed, esters and silicone oils are available on request; air temperature -25 to +50 degrees C, fluid up to 105 degrees C (115 degrees C in emergency operation); conservator height up to 5 m for the standard model, a height difference of at most 3 m between separate conservators, a minimum conservator volume per type and class, and a minimum conservator height above 2,000 m installation height.
  • Multi-column and 145 kV rules — a multi-column tap-changer needs the maximum circulating current stated by the transformer manufacturer, and at 145 kV the oil suction pipe must not be used with an oil filter unit.
  • Stated figures — the oil filling quantity and the approximate weight the order states are compared with the listed values for the type and voltage class.

Any VACUTAP VV order that touches these rules is in scope — not only the scenarios pictured here. Not covered: prices (Maschinenfabrik Reinhausen publishes no price list, so this validator produces no price build-up or line-item quote), the drive and control equipment, other VACUTAP families and other on-load tap-changers, the step capacity diagram itself, and the detailed insulation distances other than the one across the tap winding. The model reflects the technical data document read in October 2026.

The AI sales agentBuilds the tap-changer order from the conversation and says it is ready.
Predictika validatorChecks every rule at once and returns the verdict, each finding, and the computed figures.

7 scenarios in 3 groups · each group runs from the agent’s first attempt to the outcome · click one to switch

What the agent proposes

The AI sales agent says

Illustrative agent statement. The validator receives the structured request below.

Proposing agent: AI sales agent (scripted)

Before sending, the agent must call Recorded run

Predictika validator


      

        
        
        
      

      
Waiting for the call.

      
    

  

  
  

    
Where rules-based CPQ gets it wrong
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Our assessment of what a typical rules-based CPQ (product rules, price rules and validation rules, as in Salesforce CPQ) does with the same cases. It is a judgment about effort and reliability, not a claim that nothing can be built.

    
What the validator caughtTypical rules-based CPQPredictika
A step voltage limit that depends on the through-currentOnly with care
The listed maximum step voltage changes with the rating of the type and the current, so each type needs its own formula and a threshold that sends the borderline cases to a person.		The step voltage and current are in one request; a value above the hard limit blocks and a value above the lower end of the range goes to approval.
Limits that combine several fields, such as operating positions with or without a change-over selector, or a 145 kV order with both a suction pipe and an oil filter unitOnly with care
Each limit depends on a second choice, which means several linked rules for one product family.		The choices travel in one request and each combination is checked on every call.
A stated filling quantity or weight that disagrees with the type and voltage classOnly with workarounds
The listed figures are derived from the type and voltage class; checking a stated figure against them takes extra formulas that interact with the rest of the rules.		The stated figures are fields in the request and are compared with the computed ones.
Every problem returned in one answerOnly with workarounds
Rules tend to fire as the order is saved or a step is completed, so a rep often fixes one error and meets the next.		All findings come back together, whatever order the choices arrived in.

  

  

    
What this validator catches: findings from its test cases
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Every rule is checked on every call, in any order the choices arrive; one problem never hides another. Blocking findings stop the quote; approval findings need a person to sign off; everything else is computed.

    
1The order needs a through-current of 401 A, but the selected type is rated for at most 400 A.
2The order needs a through-current of 251 A, but the selected type is rated for at most 250 A.
3The order needs a through-current of 601 A, but the selected type is rated for at most 600 A.
4A highest voltage for equipment of 40 kV is not listed for the selected VACUTAP VV type (VV III is listed at 40, 76, 123 and 145 kV; VV I at 76 and 145 kV).
5A highest voltage for equipment of 110 kV is not listed for the selected VACUTAP VV type (VV III is listed at 40, 76, 123 and 145 kV; VV I at 76 and 145 kV).
6A step voltage of 2,001 V is above the 2,000 V maximum rated step voltage of the VACUTAP VV.
7For this type the maximum rated step voltage falls from 2,000 V to 1,700 V as the through-current rises; a step voltage of 1,701 V needs checking against the step capacity diagram.
8For this type the maximum rated step voltage falls from 2,000 V to 1,000 V as the through-current rises; a step voltage of 1,001 V needs checking against the step capacity diagram.
913 operating positions are above the listed maximum of 12 for this selector arrangement (12 without a change-over selector, 23 with one).
1024 operating positions are above the listed maximum of 23 for this selector arrangement (12 without a change-over selector, 23 with one).
11The order needs a short-time current of 7 kA; the listed rated short-time current is 6 kA.
12The order needs a short-circuit duration of 4 s; the listed rated duration is 3 s.
13The order needs a peak withstand current of 16 kA; the listed rated peak withstand current is 15 kA.
14A rated frequency of 61 Hz is outside the listed 50 to 60 Hz range.
15A rated frequency of 49 Hz is outside the listed 50 to 60 Hz range.
16The order needs 201 kV lightning impulse withstand across the tap winding; the listed value for this voltage class is 200 kV.
17The order needs 251 kV lightning impulse withstand across the tap winding; the listed value for this voltage class is 250 kV.
18The operating air temperature range of -26 to 45 degrees C is outside the permitted -25 to +50 degrees C.
19The operating air temperature range of -20 to 51 degrees C is outside the permitted -25 to +50 degrees C.
20An insulating fluid temperature of 110 degrees C is above the 105 degrees C permitted in operation and is allowed only in emergency operation up to 115 degrees C.
21An insulating fluid temperature of 116 degrees C is above the permitted 105 degrees C in operation and 115 degrees C in emergency operation.
22Natural or synthetic esters and silicone oils are available on request only; a person should confirm the insulating fluid with the manufacturer.
23The standard model is designed for an oil conservator height of up to 5 m; the order has 5.5 m, so a person should confirm the design with the manufacturer.
24Above 2,000 m installation height a minimum oil conservator height must be observed; a person should confirm it for an installation height of 2,001 m.

  

  

    
Scenarios and results
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The recorded result of the validator for each scenario on this page: the request the AI agent sent, the verdict, and every finding, in the order they appear above.

    
1. Standard transformer order: A VV III 400 with 450 A and 14 positions

    
The agent's request. Please quote a VACUTAP VV III 400 on-load tap-changer for 76 kV with a through-current of 450 A, a step voltage of 1,900 V and 14 operating positions, with no change-over selector, filled with mineral insulating oil up to 95 degrees C, for an air temperature of -20 to 45 degrees C, with an oil conservator of 120 litres. The order states an oil filling quantity of 240 litres and a weight of 255 kg. It is ready to send.

    
Verdict: Blocked.

    
    
      
  • Through-current above the type rating. The order needs a through-current of 450 A, but the selected type is rated for at most 400 A.
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  • Too many operating positions. 14 operating positions are above the listed maximum of 12 for this selector arrangement (12 without a change-over selector, 23 with one).
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  • Stated filling quantity differs from the listed one. The order states an oil filling quantity of 240 litres, but the listed filling quantity for this type and voltage class is 265 litres.
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  • Step voltage needs the step capacity diagram. For this type the maximum rated step voltage falls from 2,000 V to 1,700 V as the through-current rises; a step voltage of 1,900 V needs checking against the step capacity diagram.
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2. Standard transformer order: The agent resubmits after fixing the errors

    
The agent's request. Please quote a VACUTAP VV III 600 on-load tap-changer for 76 kV with a through-current of 450 A, a step voltage of 1,000 V and 14 operating positions, with a reversing change-over selector, filled with mineral insulating oil up to 95 degrees C, for an air temperature of -20 to 45 degrees C, with an oil conservator of 120 litres. The order states an oil filling quantity of 265 litres and a weight of 255 kg. It is ready to send.

    
Verdict: Allowed.

    
    
      
  • Order summary. 14 operating positions, 450 A through-current, 1,000 V step voltage, 265 litres oil filling quantity, 255 kg weight without fluid.
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3. Hot, tall installation: A VV III 600 at 123 kV for a hot site with a tall conservator

    
The agent's request. Please quote a VACUTAP VV III 600 on-load tap-changer for 123 kV with a through-current of 640 A, a step voltage of 1,000 V and 21 operating positions, with a reversing change-over selector, filled with mineral insulating oil up to 120 degrees C, for an air temperature of -20 to 55 degrees C, with an oil conservator of 150 litres at a height of 6.2 m. The order states an oil filling quantity of 265 litres and a weight of 255 kg. It is ready to send.

    
Verdict: Blocked.

    
    
      
  • Through-current above the type rating. The order needs a through-current of 640 A, but the selected type is rated for at most 600 A.
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  • Air temperature outside the permitted range. The operating air temperature range of -20 to 55 degrees C is outside the permitted -25 to +50 degrees C.
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  • Insulating fluid temperature too high. An insulating fluid temperature of 120 degrees C is above the permitted 105 degrees C in operation and 115 degrees C in emergency operation.
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  • Oil conservator higher than the standard model. The standard model is designed for an oil conservator height of up to 5 m; the order has 6.2 m, so a person should confirm the design with the manufacturer.
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4. Hot, tall installation: The agent resubmits after fixing the errors

    
The agent's request. Please quote a VACUTAP VV III 600 on-load tap-changer for 123 kV with a through-current of 600 A, a step voltage of 1,000 V and 21 operating positions, with a reversing change-over selector, filled with mineral insulating oil up to 108 degrees C, for an air temperature of -20 to 50 degrees C, with an oil conservator of 150 litres at a height of 6.2 m. The order states an oil filling quantity of 265 litres and a weight of 255 kg. It is ready to send.

    
Verdict: Needs approval.

    
    
      
  • Oil conservator higher than the standard model. The standard model is designed for an oil conservator height of up to 5 m; the order has 6.2 m, so a person should confirm the design with the manufacturer.
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  • Fluid temperature in emergency range. An insulating fluid temperature of 108 degrees C is above the 105 degrees C permitted in operation and is allowed only in emergency operation up to 115 degrees C.
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  • Order summary. 21 operating positions, 600 A through-current, 1,000 V step voltage, 265 litres oil filling quantity, 255 kg weight without fluid.
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5. Hot, tall installation: The agent resubmits after fixing the errors

    
The agent's request. Please quote a VACUTAP VV III 600 on-load tap-changer for 123 kV with a through-current of 600 A, a step voltage of 1,000 V and 21 operating positions, with a reversing change-over selector, filled with mineral insulating oil up to 100 degrees C, for an air temperature of -20 to 50 degrees C, with an oil conservator of 150 litres at a height of 4.8 m. The order states an oil filling quantity of 265 litres and a weight of 255 kg. It is ready to send.

    
Verdict: Allowed.

    
    
      
  • Order summary. 21 operating positions, 600 A through-current, 1,000 V step voltage, 265 litres oil filling quantity, 255 kg weight without fluid.
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6. 145 kV multi-column order: A multi-column VV III at 145 kV with a suction pipe and an oil filter unit

    
The agent's request. Please quote a VACUTAP VV III 250 on-load tap-changer for 145 kV with a through-current of 250 A, a step voltage of 1,800 V and 21 operating positions, with a coarse tap change-over selector, filled with mineral insulating oil up to 95 degrees C, for an air temperature of -20 to 45 degrees C, with an oil conservator of 30 litres, as a multi-column arrangement, with an oil suction pipe and an oil filter unit. The order states an oil filling quantity of 325 litres and a weight of 280 kg. It is ready to send.

    
Verdict: Blocked.

    
    
      
  • Circulating current not stated. A multi-column tap-changer can have circulating currents from asynchronous switching, and the transformer manufacturer must state the maximum circulating current; none is stated.
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  • Oil suction pipe with oil filter unit. For the 145 kV series the oil suction pipe must not be used together with an oil filter unit.
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  • Oil conservator too small. The order has an oil conservator volume of 30 litres; this type and voltage class needs at least 39 litres.
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7. 145 kV multi-column order: The agent resubmits after fixing the errors

    
The agent's request. Please quote a VACUTAP VV III 250 on-load tap-changer for 145 kV with a through-current of 250 A, a step voltage of 1,800 V and 21 operating positions, with a coarse tap change-over selector, filled with mineral insulating oil up to 95 degrees C, for an air temperature of -20 to 45 degrees C, with an oil conservator of 45 litres, as a multi-column arrangement with the maximum circulating current stated by the transformer manufacturer, with an oil suction pipe. The order states an oil filling quantity of 325 litres and a weight of 280 kg. It is ready to send.

    
Verdict: Allowed.

    
    
      
  • Order summary. 21 operating positions, 250 A through-current, 1,800 V step voltage, 325 litres oil filling quantity, 280 kg weight without fluid.
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Narration transcript
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The text of the narrated walkthrough, step by step.

    
    
      
  1. Welcome to a demo of Predictika's Validator. An AI sales agent prepares an order for a VACUTAP VV on-load tap-changer with a type, a voltage class, a through-current. Before it goes out, the agent sends it to Predictika, which checks it against a declarative model of the technical data Maschinenfabrik Reinhausen publishes and returns a verdict, every reason and the figures it computed.
    2. 
      
  2. I will start with the first request by the agent.
    3. 
      
  3. The agent says. Please quote a VACUTAP VV III 600 on-load tap-changer for 123 kV with a through-current of 640 A, a step voltage of 1,000 V and 21 operating positions. The order states an oil filling quantity of 265 litres and a weight of 255 kg. The rest of the request is on screen.
    4. 
      
  4. Before it goes out, the agent calls the validator.
    5. 
      
  5. Blocked, with three findings and one approval, all in one answer. The order needs a through-current of 640 A, but the selected type is rated for at most 600 A. The operating air temperature range of -20 to 55 degrees C is outside the permitted -25 to +50 degrees C. An insulating fluid temperature of 120 degrees C is above the permitted 105 degrees C in operation and 115 degrees C in emergency operation.
    6. 
      
  6. The validator returned three blocking findings and one approval in one answer. A check that reads one field at a time would pass most of this; it shows only when the choices in the quote are checked against each other.
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  7. What this shows: for a step voltage limit that depends on the through-current, a rules-based CPQ is error-prone for this.
    8. 
      
  8. Now the agent resubmits.
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  9. The corrected request. It changes the through-current to 600 A, the fluid temperature, maximum to 108 degrees C and the air temperature range to -20 to 50.
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  10. It calls the validator again.
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  11. Not blocked, but held for a person.
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  12. The three blocking findings are cleared; two approvals remain for a person: oil conservator higher than the standard model and fluid temperature in emergency range.
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  13. The agent resubmits once more.
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  14. The revised request. It changes the fluid temperature, maximum to 100 degrees C and the oil conservator height to 4.8 m.
    15. 
      
  15. It calls the validator once more.
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  16. This time the validator clears it.
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  17. Both earlier findings are cleared, and the validator's figure matches the quote.
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  18. Four problems caught in one call, fixed in two passes, and a clean quote. That is the value of Predictika's validator: catching mistakes before they reach the customer. Now you can try the other scenarios yourself.
    19.