Sauna & locker lock: how the card hierarchy actually works
Master, pass, user, service and clear cards — what each one can and cannot do, why the master card deliberately cannot open a door, how to switch between single-card and double-card mode, and what to do when a card is lost.
The five card roles
A locker lock is not one key and one door. It is a small permission system, and it only makes sense once you see that each card is defined as much by what it cannot do as by what it can.
| Type | Colour | Can do | Cannot do |
|---|---|---|---|
| Master card | Yellow | Adds and deletes every other card in the lock. This is the only card that can authorise a pass, user or service card. | Cannot open the lock. This is deliberate — the person who administers the system should not be able to quietly open a guest’s locker. |
| Pass / manager card | Red | Emergency override — opens the lock when a guest card is lost. Held by the duty manager, not left at reception. | Cannot add or delete cards. On an empty lock, touching it three times runs a self-test: LEDs alternate, the bolt cycles, the buzzer sounds on each action. |
| User / guest card | Blue | Opens the locker. In single-card mode it works alone; in double-card mode it must be presented together with the service card. | Cannot manage other cards. Note that a guest card can be any TM90 key of any family code — only the management cards must be our dedicated cards. |
| Service card | Green | Used in double-card mode: the locker only opens when guest and staff present their cards together — the standard control for spa and gym changing rooms. | Cannot manage cards. If no service card is programmed, the lock is in single-card mode by definition. |
| Clear card | — | Wipes every authorised card from the lock — including the master — when combined with a service or guest card. Crucially, this works without dismantling the lock from the door. | Needs no prior authorisation, which is exactly why it must be controlled like a key to the building. |
Single-card and double-card mode
Double-card mode means guest and staff must both present a card — used where a venue wants no unaccompanied locker access. Switching back to single-card mode is done by touching the master card twice, which deletes the service cards. If no service card is programmed, the lock is already in single-card mode.
When a card is lost
Lose a pass, user or service card and the master card simply issues a replacement — the lost one stops working the moment the new one is added. Lose the master card and there is no shortcut: the lock has to be emptied and every card re-issued. That asymmetry is the reason the master card should live in a safe, not on a keyring.
Electrical specifications
| Parameter | Sauna type (TM12) | Cabinet type |
|---|---|---|
| Working voltage | DC 6 V (4 × AA) | DC 4.5 V (3 × AA) |
| Working current | 200 mA-PP | 100 mA-PP |
| Standby current | 30 µA | 1 µA |
| Low-battery alarm | < 4.8 V | 3.3 – 3.4 V |
| Operating environment | −40 … +85 °C, RH ≤ 98% | −40 … +85 °C, RH ≤ 98% |
| ESD immunity | +15 kV | ±15 kV |
| Probe attack resistance | — | ≥ 250 V sustained AC/DC |
| Body size | 125 × 65 × 25 mm | 125 × 65 × 25 mm |
This table is provided as a working reference. For design-critical decisions always confirm against the current manufacturer datasheet.
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