Overview
Manuals
Dual Output Loops
Open-Wire Checks
Isolator Ratings
Features:
- Sixteen 4–20 mA output paths using eight dual-channel MTL4549C isolators on a nominal 6-inch non-redundant IOTA.
- Documented isolator functions include a HART signal path and open-wire detection; complete-loop capability depends on the installed electronics and field device.
- Separate IOM and isolator feeds use F1 and F2, with two 1 A fuses identified as spare part 51190582-210.
The Honeywell CC-GAOX21 is a compact termination assembly for Series C galvanically isolated analog outputs. The manufacturer's exact hardware matrix specifies sixteen channels, a 6-inch board and eight MTL4549C isolators. Each isolator handles two output paths, and the exact-model section excludes IOM redundancy. The assembly therefore belongs to the analog output connection system rather than the cabinet power-supply system. The output IOM, isolators and field loads remain separate components whose ratings and compatibility must be considered together.
In operation, the associated IOM sends control signals through the MTL4549C interfaces to compatible 4–20 mA field equipment. Honeywell describes applications involving current-to-pressure transducers and position actuators, and illustrates the signal route and shield-grounding reference in the model's wiring diagram. HART use requires a suitable HART IOM and field device as well as the supported isolator path. Before replacement, preserve channel assignments, confirm the actual isolator population and inspect the IOM and isolator feed protection. The 70 mA and 1.6 W figures in the isolator table describe each MTL4549C under the stated conditions, not the consumption of a fully populated IOTA.
The CC-GAOX21 Honeywell Non-Redundant GI/IS Analog Output IOTA may still be available for purchase and support from Moore Automated Company beyond End-Of-Life (EOL) by the manufacturer (OEM).
Honeywell CC-GAOX21 official technical documentation and product links.
This multi-page Honeywell technical document contains the exact model and its technical data. Apply the values to the supplied type number and verify its revision before installation.
CC-GAOX21 uses eight MTL4549C isolators to serve sixteen output channels. Each dual-channel position must retain its assigned pair of field circuits during maintenance. Follow the model-specific connection diagram for current polarity and shield grounding. The single-channel MTL4546C option listed for CC-GAOX11 is not an approved alternative in the CC-GAOX21 exact-model description.
Honeywell identifies open-wire detection as a function of the supported MTL4549C isolator. When a loop fault is reported, verify the affected channel, field load, wiring continuity and applicable IOM diagnostics under the site's maintenance procedure. The isolator's capability does not justify assigning a detection threshold or diagnostic response time that the reviewed exact-model source does not specify.
The MTL4549C column states a 70 mA supply requirement at 24 V and a maximum 1.6 W dissipation at 24 V with a 20 mA signal. It also lists 250 Vac isolation between hazardous-area and safe/power-supply circuits and temperature drift below 1.0 microampere per degree Celsius. These are isolator ratings, not total-board consumption or IOM output accuracy.
