Heraeus HS 12, Руководство по обслуживанию, Страница: 71 / 282

Service Instructions HERAsafe HS/12/18
• 42 •
Valid: 05.2001 / 50060091 / A
B. Testing for ground circuit resistance:
1. Place all electrical switches in the ”off” position.
2. Plug the ESA power plug into the outlet of the
mains supply.
3. Connect the safety cabinet power plug to the ESA
ground circuit resistance adapter.
4. Read and record the value.
C. Testing for polarity and ground faults:
1. Unplug all accessories from the cabinet-internal
power supply.
2. Check to see if the connection line of the cabinet-
internal power supply is connected to the mains
supply.
3. Set the GFI tester to ”polarity” and test each cabi-
net power outlet. When the polarity is correct, the
two yellow lights will light equally. Any other com-
bination of lights indicates a fault as identified on
the tester.
4. On units with ground fault interrupters, unplug all
accessories from the cabinet-internal power out-
lets. Plug the tester into the last connected re-
ceptacle in the GFI protected branch.
5. Turn the tester selector switch to 1, 2, and 3 mA
positions. If leakage is detected, the lights will go
out indicating leakage in the safety cabinet.
NOTE – Duplex power supply:
The safety cabinets are equipped with two
power supply connections: one connection for the
cabinet and a separate connection for the cabinet
outlets.
The electrical safety tests must be performed for both
connections!
B3 Electrical safety test
Purpose of the test:
This test is performed to check the electrical safety
after the cabinet has been installed and to perform the
annual safety inspection.
The following tests are performed:
 Electrical leakage test,
 Ground resistance test,
 Polarity test.
Apparatus :
Electrical safety analyzer (ESA) with 1 k  input im-
pedance and two leads:
 One lead with a sharp point,
 One lead with a probe.
Circuit tester.
Calibration of the apparatus:
Calibration performed by manufacturer.
Auxiliary devices:
Adapter with 3-hole electrical receptacle on one end
and a two-prong plug on the other end.
Perform the test measurement:
A. Testing for electrical leakage:
1. Place all electrical switches in the ”off” position.
2. Plug the ESA power plug into the outlet of the
mains supply.
3. Connect the safety cabinet power plug to the ESA
leak current adapter.
4. Turn the ESA function selector to the microamp
(mA) scale. Read and record the displayed value.
5. Turn on all the switches of the safety cabinet.
Read and record the displayed value.
B Field tests