TM 9-6115-604-34
NAVFAC P-8-633-34
(6)
Disconnect 120 V ac power supply.
(7)
Check resistance of coil. Resistance should be 246 to 334 ohms.
(8)
Replace emergency light relay K100 if readings are incorrect or out of tolerance as indicated in steps (2),
(4), and (7), above.
d.
Install.
(1)
Install emergency light relay K100 (56, Figure 5-9) and secure with screw and captive washer assemblies
(57).
(2)
Make wiring connections as necessary and discard wire tags.
(3)
Install relay cover and secure with screws.
5-32. 50 HERTZ AND 60 HERTZ FREQUENCY RELAYS K108 AND K107 (58 and 59, Figure 5-9). The 50 hertz and
60 hertz frequency relays are boated inside cabinet B. The units are identical. Either relay may be set to trip anywhere
over a frequency range of 45 to 66 hertz. Unless otherwise specified, the following procedures apply to both K108 and
K107.
a.
Inspect.
(1)
Inspect screw and captive washer assemblies (60, Figure 5-9) and electrical connections for security.
(2)
Examine wires connected to 50 hertz and 60 hertz frequency relays for evidence of burning or insulation
breakdown.
b.
Remove. See Figure 5-9.
(1)
Tag and disconnect wires to relay terminals.
(2)
Remove 50 hertz and 60 hertz frequency relays K108 and K107(58 and 59) by removing screw and captive
washer assemblies (60).
c.
Test and Adjust.
(1)
Connect a variable frequency 120 V ac power supply across relay terminals 1 and 2. Apply 120 V ac, 50
Hz to the K108 relay. Apply 120 V ac, 60 Hz to the K107 relay.
(2)
Connect a multimeter set to RX1 across the NC terminals. Multimeter should read infinite ohms. If
reading is not infinite ohms, consider relay to have tripped above maximum and adjust in accordance with
step (4), below.
(3)
Gradually decrease the frequency of the applied voltage until multimeter indication goes to zero ohms, 50
hertz relay K108 trips at between 45.5 and 47.5 Hz; 60 hertz relay K107 trips at 55.5 to 57.5 Hz.
(a)
If multimeter reads zero ohms at an applied frequency between 45.5 and 47.5 hertz (for K108) or
between 55.5 and 57.5 hertz (for K107), go to step (5), below.
(b)
If multimeter does not read zero ohms as specified, adjust 50 hertz and 60 hertz frequency relays in
accordance with step (4), below.
(4)
Adjust K108 or K107 as follows:
(a) Apply 120 V ac, 60 Hz across K107 terminals 1 and 2. Apply 120 V ac, 50 Hz across K108
terminals 1 and 2.
(b) The frequency trip range of each relay is adjustable. I the relay tripped above maximum
specified in step (3)(a), above, turn PICK-UP ADJUST slightly counterclockwise and repeat step (3),
above.
(c) If relay tripped below minimum specified in step (3)(a), above, turn PICK-UP ADJUST slightly
clockwise and repeat step (3), above.
(d) Repeat steps (3) and (4), above, until relay satisfies requirements of step (3)(a), above.
(5)
Apply 120 V ac, 60 Hz across K107 terminals 1 and 2. Apply 120 V ac, 50 Hz across K108 terminals 1 and
2.
(6)
Connect a multimeter set to RX1 across the NO terminals. Multimeter should read zero ohms.
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