Let me start with an opinion that has made some sales reps uncomfortable: A supplier who claims to be equally strong in ABB PLCs, VFDs, and contactors probably isn't. The more time I spend in this job, the more I trust the opposite. I'd rather hear “that's not our strength” than “we handle everything.”
I'm an office administrator for a manufacturing company with about 400 employees across three locations. I manage the electrical components budget—roughly $1.5 million last year, or rather, that's what accounting approved; the actual spend came in a little lower. I order ABB PLC spares, drives, contactors, relays, timers, and the occasional safety PLC. I've also made enough purchasing mistakes to learn a few things the hard way.
The one-stop shop myth
When I first started in this role, I assumed that consolidating everything with one distributor was the obvious move. One order, one invoice, one support number. It seemed like a no-brainer. It wasn't.
In 2020, we consolidated most of our electrical procurement with a large general-line supplier. Their rep said “we carry everything.” Three months later, we needed a batch of ABB AC500 PLCs plus a compatible drive for a packaging line. They confirmed the order, took the PO, and then went quiet. It turned out they didn't stock the AC500 CPU we specified. They planned to source it through another distributor. The drive wasn't on their shelf either. I won't recite the delivery drama here; let's just say the line sat idle longer than it should have.
The worst part wasn't the delay. It was the support. When I asked about the ABB PLC software—specifically, whether we could reuse an existing IEC 61131-3 function block library in Automation Builder—the rep said “I'm not sure.” Nobody on their team knew. They were a generalist, not an ABB controls specialist.
Catalog size isn't expertise. A supplier who stocks a bit of everything knows a little about a lot. A supplier who focuses on ABB PLCs, drives, and controls actually knows how the equipment behaves. In a breakdown, that difference is everything.
The supplier who told me “no”
Here's the moment that changed how I buy.
Last year, I called a vfd supplier about replacing a conveyor drive. They sent me a drive catalog—not a generic PDF, a shortlist with three models and a cover note: “We don't do PLC programming. If you need help with the ABB PLC logic, call the integrator we work with.”
At first, I marked them down. “You don't do PLC programming? That's a problem.” Then I thought about it. They knew what they didn't know. That's rare. They also knew exactly which drive matched our motor, voltage, and duty cycle. They flagged a compatibility issue with our existing AC500 project. The honesty made them more credible.
I went back and forth for a week. On paper, the old generalist was slightly cheaper. My gut said the specialist would keep us from repeating the 2020 disaster. I chose the specialist. For two weeks after, I second-guessed the switch. Then the drive arrived on time, with the right documentation, and I stopped worrying.
Since then, I ask every supplier: “What won't you do?”
If the answer is “we do everything,” I keep digging. If the answer is “we're great at this part, not that part,” I trust them more. Backwards, I know. It works.
What I actually ask before buying
I don't use a complicated scoring model. Five questions:
- What are you not good at? If they can't name one weakness, they haven't thought about it.
- Can you show me the ABB PLC software? Not a screenshot—a real walkthrough of Automation Builder. If they can't navigate it, they can't help when we're stuck.
- Which drive would you pick for this motor, and why? A good vfd supplier gives a recommendation. A weak one sends the whole drive catalog and says “you choose.”
- Can you show me the contactor test data? AC-1 and AC-3 ratings, coil voltage, Type 2 coordination. If someone can't explain those, they're selling metal, not motor control.
- What happens when you don't have stock? Do they tell me immediately, or do they let me find out after the promised ship date?
How to evaluate contactor manufacturers
Contactors don't get enough attention. A contactor failure can take down a panel faster than a drive fault. Here's how I evaluate contactor manufacturers: I ask about standards first. A serious manufacturer can explain IEC 60947-4-1, utilization categories, and why a contactor rated for AC-1 isn't automatically right for AC-3 duty. They ask what motor you're protecting, not just how many poles.
I'm not saying private-label or lesser-known brands are always wrong. Some are fine for simple switching. But if you're building equipment that needs documented coordination, you need a manufacturer who can show test data and explain it. That's where specialist knowledge becomes non-negotiable.
But what about convenience?
You might argue that fewer vendors means fewer POs, fewer invoices, fewer headaches. I used to think that. Then in 2024, we ran a vendor consolidation project. We cut our vendor list from nine to six. But we didn't consolidate around “everything” suppliers. We consolidated around specialists—an ABB PLC and drive specialist, and a separate contactor specialist. Total invoice count went down. So did the time I spent chasing support answers that nobody could give.
For standard jobs, a generalist can be fine. For anything with ABB AC500 PLCs, VFDs, or safety-rated controls, I want someone who knows those products cold.
This isn't about ABB's product range. ABB does make AC500 PLCs, drives, and contactors—that's part of why we spec them. But a distributor with the whole catalog can still be shallow on any given product line. I'd rather buy from a specialist who knows ABB deeply than a generalist who knows ABB vaguely.
The point
Look, I'm not saying every specialist is perfect. I've dealt with specialists who were slow, expensive, and hard to reach—I've got the invoices to prove it. But the ones on my regular list have one thing in common: they tell me when they're not the right fit. That's not a weakness. That's expertise.
So if you're evaluating an ABB PLC supplier, a VFD supplier, or a contactor manufacturer, don't start with “what can you do?” Start with “what can't you do?” The answer will tell you more than a 400-page catalog ever will.