Commercial in Confidence
Smartfind EPIRB service manual
Page 29
3.10. HRU replacement
If the EPIRB is in an enclosure marked “Category 1” (automatic, float-free version) it will
contain a Hydrostatic Release Unit (HRU). This item has a finite life and a 2 year
replacement interval. The HRU expiry date must be checked regularly. The date is
marked on the HRU itself and is repeated on the enclosure side label.
HRU replacement may be performed by the service provider or by the customer.
A replacement HRU kit is available (see spares list, section 6). This includes a new
breakable rod with washer and E-clip. We do not currently recommend using any
alternative HRUs as these will not be supplied with a new breakable rod, forcing the re-
use of the old rod, which is undesirable.
The replacement procedure is as follows:
1. On the enclosure, remove the R-clip and pull the cover slowly off.
2. Remove the EPIRB and stow it in a dry place.
It will activate if wet.
3. Push down the lever arm to take up the force of the spring.
4. Push the HRU back then upwards, out of the slot in the lever arm.
5. When the rear clip disengages slowly release the lever arm.
6. The HRU with its breakable rod can now be lifted free and replaced.
7. Locate the new HRU complete with breakable rod.
8. Mark the HRU with an expiry date 2 years from the date of installation.
9. Slide the HRU into the slot in the lever arm and push lever arm back.
10. Engage rear washer into back plate by pushing back and sliding down.
11. Look under the spring and confirm that the washer is fully engaged.
12. Slide EPIRB into D-shaped foot on lever arm (switch to the right when HRU is
at the top) and fold the antenna into its location position.
13. Refit cover by engaging hole over rod and then snapping into place.
14. Refit R-clip in the slot in the top of the rod.
15.
On side of enclosure, mark new HRU expiry date, over old date.
