AT&T System 85 manual Irob Protection, Itw

EXPOSED PORT PROTECTION

TABLE 2-D. IROB Protection

CIRCUIT	TERMINAL	REQUIRED	SEE
PACKS		PROTECTOR*	NOTE
SN224	7203,	EP	—
	7205,
	MET
SN228B,	2500 Series,	P	1
SN229	2500DMGC,
	7100 Series
TN742,	500 Series,	P	1
TN746B,	2500 Series,
TN769	7100 Series
SN270	7400 Series	EP	—
TN754	7400 Series	(ITW)	2
TN754, V14	7400 Series	EP	3
TN556	T. Term	EP & P	4

*P = Primary, EP = Enhanced Primary

Notes:

1.Primary protection with heat coils for sneak protection are coded with the number 4 as the first numeric. DEFINITY ports require sneak current protection for IROB terminal installations.

2.The TN754, V1 through V13 may be installed with either the DLP and primary protector or the ITW Linx Enhanced Primary protector. These vintages may not be installed with the 4C3S-75 Enhanced Primary protector.

3.The 4C3S-75 Enhanced Protector may only be used on Vintage 14 or newer TN754 Circuit Packs. The ITW Linx Enhanced Protector may be used on all Vin- tages of the TN754 Circuit Pack.

4.The TN556 Circuit Pack requires Enhanced Primary protection at the port and Primary (3- or 4-type) protection at the terminal.

For more information on exposed port protection, refer to:

DEFINITY Communications System Generic 1 and Generic 3 Wiring, 555-204-111

DEFINITY Communications System Generic 2 and System 85 Wiring, 555-104-630

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