Safe Access to Shaft Procedure
It is recommended to follow this safe access procedure to enter the shaft for maintenance purposes without the system being stopped due to the interruption of the safety chain (opening of the landing doors).
With the lift in normal mode:
1 – Keep the doors open by holding down the DOOR OPEN button and pushing three times the button corresponding to the current floor.
2 – The car panel will emit a continuous sound to warn of the activation of the “Safe Shaft Access” mode that temporarily excludes all calls and maintains the doors open (You can exit this mode by pressing the door open button again).
3 – Exit the Cabin.
4 – The lift controller will close the doors and move the cabin 2 meters down (or up 2,5 meters if the car is at lowest floor).
5 -See the next steps for access to pit or car roof.
Notes: if the door is not open within 10s the lift returns to normal service.
IMPORTANT: Access to the shaft for EN81-21-compliant lifts requires that, after access and subsequent exit from the shaft by an authorized person, a specific reset procedure that excludes the automatic return to normal operation must be performed. See below for specific instructions.
Access to Shaft in EN81.21 lifts
According to EN81.21 standard (1), when the minimum required operating space for the lift headroom and/or pit in the (existing) building cannot be guaranteed to technicians, it must be ensured that the necessary safety spaces are automatically created by mechanical protection devices that prevent the maintenance worker from being injured by unwanted movement of the cabin in the shaft.
(1): The lift must be designed and manufactured in order to prevent the risk of crushing when the elevator car is in an extreme position. In order to achieve this, a free space or refuge beyond the extreme positions must be provided. However, in exceptional cases, allowing the Member States the possibility of giving prior approval, particularly in existing buildings, the competent authorities may provide other appropriate means to avoid this risk, if the previous solution is impossible to achieve.
The Pitagora 4.0 controller is designed to handle different Protection devices to comply with the EN81.21 prescription. A specific safety circuit is in place to detect any access to the shaft. Upon opening of one of the doors, the controller logic activates a dedicated fault in the system and imposes a specific reset procedure before allowing the return to normal operations.
The controller reacts differently based on the lift configuration:
Access to Pit in lifts with reduced headroom
Access to the pit in lifts with reduced headroom does not need to be protected according to EN81.21 prescriptions. This case falls under the previous EN81.20 case (see Access to Pit in EN81.20 lifts).
Access to car top in lifts with reduced headroom
Access to the car top in lifts with reduced headroom must be protected by means of a NC, bistable or monostable door contact on all floor doors that activates a safety circuit inside the controller. An auxiliary NC door contact can also be connected to the BDU’s door input or to the lift controller (E511 input) to facilitate the reset procedure (see Access to Pit in EN81.20 lifts).
Access to the shaft is detected by opening any floor door (triangular key). This activates Fault 40.21 – Access to Shaft and prevents the movement of the lift in normal mode (movement is allowed in Inspection mode only).
To enter the shaft and start the maintenance on the top of the car it is necessary to enter the pit first and activate the manual protection (if applicable):
1 – Open the lowest door (triangular key) – The safety circuit is engaged
2 – Press the STOP button in the pit – The RED light of the EN81.21 indicator is ON
3 – Activate the manual protection in the pit (typically below the counterweight) – The GREEN light is ON
4 – Place the shaft inspection box switch to INSPECTION to move the car to a place where the roof can be easily accessible from the floor.
5 – Place the shaft inspection box switch to NORMAL.
6 – Exit the pit, release the STOP button and go on the top of the car through one of the floor doors.
7 – Check that the EN81.21 on the top of the car is GREEN, then place the car top inspection box switch to INSPECTION.
You can now operate safely on the car top.
When the maintenance is over:
1 – Place the car top inspection box switch to NORMAL and exit the shaft.
2 – Open again the lowest floor door, press the STOP button and enter the pit.
3 – Remove any manual protection in the pit (if applicable) – The RED light of the EN81.21 indicator is ON
4 – Exit the shaft and release the STOP button
5 – Close the landing doors (check that the safety chain #5 and #6 are closed) and perform the specific RSP reset procedure using one of the following methods:
A) From lowest floor, with three quick opening / closing turns of the release key
B) From the service panel inside the controller, with three quick presses of down button (▼)
C) From the PlayPad with specific reset (RSP reset in the “Errors” Menu).
The lift must be now back into regular operation.
Access to Pit in lifts with reduced pit
Access to the pit in lifts with reduced pit space must be protected by means of a NC, bistable or monostable door contact on lowest floor door that activates a safety circuit inside the controller. An auxiliary NC door contact can also be connected to the BDU’s door input or to the lift controller (E511 input) to facilitate the reset procedure (see Access to Pit in EN81.20 lifts).
Access to the pit is detected by opening the lowest floor door (triangular key). This activates Fault 40.21 – Access to Shaft and prevents the movement of the lift in normal mode (movement is allowed in Inspection mode only).
To enter the pit and start the maintenance:
1 – Open the doors (triangular key) – The safety circuit is engaged
2 – Press the STOP button – The RED light of the EN81.21 indicator is ON
3 – Enter the pit and activate the manual protection in the pit (if present) – The GREEN light is ON
4 – Place the shaft inspection box switch to INSPECTION and release the STOP buttons
You can now operate safely in the pit.
When the maintenance is over:
1 – Press the STOP button
2 – Remove any manual protection in the pit (if applicable) – The RED light of the EN81.21 indicator is ON
2 – Place the shaft inspection box switch to NORMAL
2 – Exit the shaft and release the STOP button
3 – Close the landing doors (check that the safety chain #5 and #6 are closed) and perform the specific RSP reset procedure using one of the following methods:
A) From lowest floor, with three quick opening / closing turns of the release key
B) From the service panel inside the controller, with three quick presses of down button (▼)
C) From the PlayPad with specific reset (RSP reset in the “Errors” Menu).
The lift must be now back into regular operation.
Access to car top in lifts with reduced pit
Access to car top pit in lifts with reduced pit does not need to be protected according to EN81.21 prescriptions. This case falls under the previous EN81.20 case (see Access to Pit in EN81.20 lifts).
Protection devices according to EN81.21
Manual Protections
Manual protection devices include manually operated mechanical pillars positioned in the pit under the counterweight (for traction lifts with reduced headroom) and/or under the cabin (for lifts with reduced pit).
The manual devices must be equipped with safety contacts (1 NO contact + 1 NC contact for both the “Protection enabled” position (Inspection mode) and “Protection disabled” (Normal operation). Contacts are included in the safety chain both for normal operation (to prevent the lift from resuming the travel if the protection have not been removed) and for inspection mode (to ensure that any movement in inspection mode is only possible with protections enabled).
Pre-activated Protections
The pre-activated devices (certified solutions not supplied by DMG) are typically mounted on the cabin and intervene on the parachute in case of exceeding the limit positions (typically brackets fixed on the guides where the device is mechanically fitted).
The Pitagora 4.0 controller monitors the preactivated device to verify its correct position before giving the consent to moving the cabin. Upon access to the shaft in lifts with reduced spaces, the EN81.21 RED/GREEN indicators is automatically GREEN when a pre-activated device is present and functioning.
Shaft Access Control
This solution is only available with the Elgo Safe absolute encoder system, in combination with the A3-certified speed limiter. In case of exceeding the limit positions (stored in Elgo), the encoder itself triggers the speed limiter and, consequently, the parachute. Note: the speed limiter must be bidirectional and certified as a EN81-21 solution (such as Montanari limiters model RQ-A and RC).
The Pitagora 4.0 controller monitors the A3 speed limiter to verify the correct position of the retractable pin before giving the consent to moving the cabin and consequently drive the EN81.21 RED/GREEN indicators is automatically GREEN when a pre-activated device is present and functioning.
To comply with the proposed solution the pin of the A3 coil must have electrical characteristics 24 V – max 1 A.
Custom Solutions
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Electronic Parachute
See here for this solution.
