Inspect Safety Relief Devices And Piping; Periodic Check Of The Safety Loop - Carrier 19DV Series Installation, Operation And Maintenance Instructions

A : Float ball
B : refrigerant exit

9.3.9 Inspect Safety Relief Devices and Piping

Refer to chapter 1 "Safety considerations". The relief valves on this chiller protect the system against the
potentially dangerous effects of overpressure. These devices must be kept in peak operating condition.
As a minimum, the following maintenance is required:
• At least once a year, disconnect the vent piping at the valve outlet and carefully inspect the valve body and
mechanism for any evidence of internal corrosion or rust, dirt, scale, leakage, etc.
• If corrosion or foreign material is found, do not attempt to repair or recondition. Replace the valve.
• If the chiller is installed in a corrosive atmosphere or the relief valves are vented into a corrosive atmosphere,
make valve inspections at more frequent intervals.

9.3.10 - Periodic check of the safety loop

Every 6 months, check the SRMCR safety loop.
The periodic tests are intended to verify the correct functioning of the following elements:
- Opening and setting of safety switches (HPS pressure switches).
- The good opening of the contactor K101 and its return of state. .
- The proper operation of the GateKill stop function.
9.3.10.1 Checking the adjustment of safety switches
Invert the direction of the three-way valve so that the two standby switches start the operation.
Remove the first pressure switches and have their controls checked by an approved body - see Annex C,
paragraph C6 of EN 378-2.
Lock the 3-way valve to prevent any mishandling.
Once the settings have been checked, reinstall the pressure switches on the three-way valve and invert the valve
again to allow the operation of the pressure switch again.
9.3.10.2 Checking the safety chain
The verification steps are described in the tables below.
Test n ° 1:
Steps
Disconnect an active pressure switch by opening its disconnect terminal on TBS main
terminal
(SP1FA = S-11 ; SP1FB= S-12 ; SP2FA = S-21 ; SP2FB = S-22).
2- Check that the OUT LED of the safety relay K4 goes out.
3- Check that the round tap of the K101 contactor is not depressed.
Check that the alarm corresponding to the opening of the Gate Kill input is present
Fig 58 – Float ball valve details
OK NOK
Na
104