Why I stopped comparing time delay relays by unit price
I've been buying time delay relays—off-delay units, cycle timers, DIN rail timers, and a lot of industrial timers—for about six years now. I'll be honest: for the first three, I compared quotes the way most people do. Lowest unit price wins, everything else is noise.
That changed in Q3 2023 when I pulled a year of purchase data from our cost tracking system and actually looked at what we'd spent beyond the invoice line. The units were cheap. The consequences weren't.
Here's the thing about relay timers, though: there's no single "right" sourcing strategy. The right answer depends on why you're buying them. I break this into three situations—and the advice for each one is genuinely different.
Situation A: You're buying for maintenance and repair
This is the scenario I see most often in relay sourcing: a panel goes down, you need two or three replacements, and you need them this week. Maybe it's an off-delay relay that failed on a packaging line. Maybe it's a cycle timer socket that's been sitting in a drawer since 2019.
In this situation, unit price should be the last thing you negotiate.
What actually drives your cost here is downtime. If I save $12 on a relay but the line sits idle for an extra shift waiting on delivery, I've lost money. It isn't close.
My rule for this scenario: keep two approved suppliers—a primary and a backup—and stop chasing the lowest quote every time. I pay a small premium for the relationship, and in return I get priority handling when something's urgent. That's worth more than a few points of margin.
So glad I kept the backup supplier last year. I almost dropped them to consolidate spend, which would have cost us a full shift when the primary missed a delivery by three days.
"The conventional wisdom is to always get multiple quotes. My experience with 40+ relay orders suggests that for maintenance purchases, relationship consistency beats marginal cost savings. Every time."
One caveat: this only works because our volumes are predictable enough that suppliers want our account. This worked for us, but we're a mid-size industrial company with steady ordering patterns. If you're placing one or two small orders a year, you don't have that leverage—and you probably should quote-shop each time.
Situation B: You're buying for scheduled production
This is different. Here you have a BOM, you know you need roughly 200 time delay relays per quarter, and the units go into machines you build on a schedule.
In this scenario, total cost of ownership (TCO) is the only comparison that matters—and the lowest unit price is frequently the highest-TCO option.
What goes into the TCO calculation for a scheduled relay purchase:
- Base unit price adjusted for tiered-volume breaks
- Warranty and return terms—a single failed relay batch can cost you a full production run
- Freight and consolidation—multiple small shipments usually cost more than one consolidated PO
- Specification risk—the cost of assembly discovering mid-line that the DIN rail timer won't fit their enclosure
- Lead-time certainty—a promised date that slips costs more than a slightly higher price with a firm date
Real example. In 2022 I had two quotes for what looked like identical cycle timers. Vendor A was 22% more expensive per unit. Vendor A also quoted firm four-week lead times, a 90-day return window, and pre-paid freight. Vendor B quoted "6–8 weeks, pending stock," freight billed at actual, and a 30-day return window.
We went with A. Not because of the price, and not because of the relationship—because when I ran the numbers on risk-adjusted cost, the "cheaper" vendor cost more.
That was the order that changed how I think about relay sourcing. I stopped comparing quotes line-by-line and started comparing scenarios.
Situation C: You're sourcing for a new design or a prototype build
This is the scenario almost nobody writes about, and it's where I see the most expensive mistakes.
If you're buying industrial timers for a machine design that hasn't been validated yet, you're not really buying the cheapest unit. You're buying flexibility.
What does flexibility cost? It's the difference between a supplier who can ship you five samples next week with datasheets and a technical contact you can argue with—and a supplier who wants a 500-unit minimum and answers emails in five business days.
In this situation, I expect to pay 20–40% more per unit than the "optimized" price. And I'm fine with it, because if the design changes—and it will—I'd rather lose that markup than lose the engineering window.
Two things I've learned to insist on here:
- Ask for the spec sheet before the quote, not after. Relay timers look identical in photos and differ in timing ranges, contact ratings, and enclosure compatibility. I've been burned by ordering on a photo.
- Request samples in writing and actually test them in your panel. If a supplier won't send samples, that's your answer—not a future cost problem, but a "this supplier is wrong for this situation" problem.
On certifications, ask for the paperwork up front. The relevant reference standards for time delay relays—IEC 61812-1 for industrial time relays, UL 508 for industrial control equipment—are things a supplier should be able to point to in writing upon request. I don't need to relist every standard in a quote; I need a supplier who can produce documentation when a procurement audit asks for it. A supplier who can't is a supplier I can't defend.
How to figure out which situation you're actually in
The one-sentence test
Before you send out an RFQ, write one sentence: What would go wrong if this relay arrives late or wrong? The answer tells you which scenario you're in.
- If a relay failure stops your line, you're in Situation A—regardless of how much volume you bought.
- If your needs are forecastable by quarter and traceable to a build schedule, you're in Situation B.
- If the relay is going into a design that hasn't shipped to a customer yet, you're in Situation C.
Real procurement is messier than this. You can be in all three at once—most teams are. The point isn't to fit perfectly into a box. It's to stop applying B-scenario logic (lowest TCO on paper) to a C-scenario problem (we don't even know the final design yet).
My experience here is based on about six years of medium-volume procurement at a mid-size industrial company—maybe 60 relay orders a year across all three scenarios. If you're sourcing for a much larger operation with dedicated supply-chain engineering, some of these principles translate but the mechanics won't. If you're a one-person shop, none of the relationship math up there applies. Your mileage will vary.
The short version
Maintenance purchases: buy relationship and availability. Scheduled production: buy TCO. New design: buy flexibility. None of these favor the same supplier, and none of them favor the same quote.
If I'd known this six years ago—or at least before the 2022 order that taught me the hard way—I'd have saved us a lot of money and more time than I want to calculate. The cheapest quote on paper and the cheapest purchase in reality are rarely the same thing, and the gap is where procurement people actually earn their salary.