Timer Delays TD69 & TD73 are adjustable timer delays (time delay relays) that help protect HVAC systems from short cycling. They’re a simple add-on when you need a start or stop delay to keep equipment running smoother.
They’re quick to wire with 1/4" quick-connect terminals, and you can dial in the delay you need without guesswork.
Best for: HVAC techs, installers, maintenance teams, and switched-on DIYers doing repairs or upgrades where short cycling is causing stress on the system.
Compatible with: HVAC control circuits where a timed delay is required. If you’re running a different voltage or control setup, confirm wiring and specs before ordering/installation.
Features
- Helps reduce short cycling to protect compressors and controls
- 1/4" male quick connect terminals for faster wiring
- TD69: Adjustable delay on make (start delay)
- TD73: Adjustable delay on break (stop delay)
- Simple dial-style adjustment for quick setup
- Jumper option for use with 110/250V systems (cut jumper wire as required)
Technical Specifications
- Product type: Timer delays / time delay relays
- Terminals: 1/4" male quick connect
- TD69 function: Delay on make (start delay)
- TD69 range: 6 seconds to 8 minutes
- TD73 function: Delay on break (stop delay)
- TD73 range: 6 seconds to 5 minutes
- Voltage note: Cut jumper wire to use with 110/250V systems (follow the included instructions)
What’s in the Box
- 1 x TD69 timer delay relay (delay on make), or
- 1 x TD73 timer delay relay (delay on break)
Why “Short Cycle Protection”?
- Gives the system a breather between cycles
- Helps avoid rapid on/off starts that wear components faster
- Can improve stability after power blips or quick thermostat calls
- Easy way to add control without changing major parts
- Adjustable timing so you can suit the job, not guess it
Using Your Timer Delays: Step-by-Step
- Isolate power to the unit at the switchboard and confirm it’s off.
- Identify whether you need a delay on make (TD69) or delay on break (TD73).
- Mount the relay where it’s protected and wiring is neat (avoid heat and moisture).
- Connect wiring to the 1/4" quick connect terminals as per the wiring diagram.
- If required for your system, cut the jumper wire for 110/250V use (follow included instructions).
- Set the delay time on the dial (start at the lower end, then fine-tune).
- Restore power, test operation, and confirm the delay behaves as expected.
Limitations & Safety Notes
- Electrical work should be carried out by a licensed person where required.
- Confirm the correct model (TD69 vs TD73) for your control goal before installing.
- Confirm voltage and wiring requirements before making any changes.
- Do not work on live electrical components—always isolate and test.
- Install in a protected location away from water, corrosion, and extreme heat.
- If you’re unsure, check the unit wiring diagram or speak with a qualified technician.
Shipping & Returns
We ship Australia-wide. For dispatch timeframes, delivery info, and return steps, please see our Shipping & Returns page.
Timer Delays FAQs
What’s the difference between TD69 and TD73?
TD69 is a delay on make (it delays the start). TD73 is a delay on break (it delays the stop). Choose based on whether you want to slow down switching on or switching off.
What delay range do they cover?
TD69 adjusts from 6 seconds to 8 minutes. TD73 adjusts from 6 seconds to 5 minutes.
Are these used to prevent short cycling?
Yes. These timer delays are commonly used to reduce rapid on/off cycling, which can be hard on compressors and control gear.
Can I use this on 110/250V systems?
The TD series includes a jumper option—cut the jumper wire for 110/250V use as per the included instructions. Always confirm suitability for your exact unit before install.
How do I choose the right delay time?
Start with a shorter delay, test, then increase only if needed. You want protection from quick cycling without making the system feel sluggish.
What should I check before ordering?
Confirm whether you need a start delay (TD69) or stop delay (TD73), confirm your control voltage and wiring, and check you have a safe mounting spot inside the unit.
Why Buy From HVAC Shop
- Aussie-based support from people who know HVAC parts
- Fast shipping Australia-wide
- Trade-friendly HVAC controls and electrical spares
- Secure checkout
- Help with sizing and compatibility checks
Want the complete setup? Shop our HVAC controls and parts range for more relays, controls, and electrical essentials.