Issue
The purpose of this Resolution is to inform users of 24vdc Momentum I/O Bases that the fusing requirement has changed.

Using a 315ma fast blow fuse on a redesigned 24vdc Momentum base may cause the fuse to blow when powered up. Since the 24vdc Momentum I/O bases have been redesigned to meet the new EMC and power hold-up requirements, it was necessary to increase the size of the external fusing.

The external fusing is indicated in the User Manuals as follows. It does not affect the recommended fusing for the I/O power.

Product Line
Momentum


Environment


Resolution
The recommended size of the external fuse for all Momentum I/O modules that are powered by 24 VDC, has changed from a 315ma Fast Blow fuse to a 1Amp Slow Blow fuse (Bussmann GDC-1A or equivalent).

The 1A Slow Blow fuse can be used on both new and old versions of 24vdc powered Momentum I/O bases listed below.

DC Discrete Modules

• 170ADI34000 24V DC - 16 Pt Input Module Base
  170ADI34000C 24V DC - 16 Pt Input Module Base Coated
  170ADI35000 24V DC - 32 Pt Input Module Base
  170ADI35000C 24V DC - 32 Pt Input Module Base -Coated
  170ADM35010 24V DC - 16 Pt Input/ 16 Pt Output Module Base
  170ADM35010C 24V DC - 16 Pt Input/ 16 Pt Output Module Base Coated
  170ADM35011 24V DC - 16 Pt Input/ 16 Pt Output - Fast Response Module Base
  170ADM35015 24V DC - 16 Pt Input/ 16 Pt Output Module Base - True Low Signals
  170ADM39010 24V DC - 16 Pt Input/ 12 Pt Output - Monitored Module Base
  170ADM39030 24V DC - 10 Pt Input/ 8 Pt Relay Output Module Base
  170ADM39030C 24V DC - 10 Pt Input/ 8 Pt Relay Output Module Base Coated
  170ADO34000 24V DC - 16 Pt Output Module Base
  170ADO34000C 24V DC - 16 Pt Output Module Base Coated
  170ADO35000 24V DC - 32 Pt Output Module Base
  170ADO35000C 24V DC - 32 Pt Output Module Base Coated
  170ADM85010 10 to 60 V DC - 16 Pt Input/ 16 Pt Output Module Base

• 170AAI03000 Analog - 8 Ch Differential Input Module Base
  170AAI03000C Analog - 8 Ch Differential Input Module Base Coated
  170AAI14000 Analog - 16 Ch Single-Ended Input Module Base
  170AAI14000C Analog - 16 Ch Single-Ended Input Module Base Coated
  170AAI52040 Analog - 4 Ch RTD, Thermocouple, and Mv Input Module Base
  170AAI52040C Analog - 4 Ch RTD, Thermocouple, and Mv Input Module Base Coated
  170AAO12000 Analog - 4 Ch Output 0-20mA Module Base
  170AAO92100 Analog - 4 Ch Output 4-20mA Module Base
  170AAO92100C Analog - 4 Ch Output 4-20mA Module Base Coated
  170AMM09000 Analog - 4 Ch In/ 2 Ch Out Module Base, w/ 24V DC 4 In/2 Out Digital
  170AMM09000C Analog - 4 Ch In/ 2 Ch Out Module Base, w/ 24V DC 4 In/2 Out Digital Coated
  170AMM09001 Analog - 4 Ch In/ 2 Ch Out Module Base, w/ 12V DC 4 In/2 Out Digital

• 170AEC92000 High Speed Counter Module Base