Difference Between Integrating and Non-Integrating Ross Hill AC Modules
Rig electricians may be confused by the terms 'integrating' and 'non-integrating' with respect to Ross Hill AC Modules. This article explains the difference.
Older Ross Hill and Hill Graham SCR Systems may have been fitted with 'non-integrating' AC Modules, typically of revision W and earlier. Later systems would have been fitted with the newer 'integrating' type. Rigs which were originally fitted with 'non-integrating' modules may have been upgraded to the newer type, or have had the older revision modules modified. But what does 'integrating' and 'non-integrating' mean?
The 'integrating' or 'non-integrating' refers to the characteristic of the KW regulator portion of the AC Module.
The non-integrating type have only proportional control, which essentially means they are not as accurate in KW load sharing, and require the engine actuators' geometry to be set up so that the engines share KW load. Typically this set up is made so that the AC Module delivers 20-30mA throttle current at full-speed, no-load. This does not guarantee good load sharing across the range, and there may be an imbalance at light or heavy loads. In general, fine tuning is done to achieve the best load sharing at full load.
The integrating KW regulator was introduced to address these load sharing issues. By incorporating an integral term into the regulator load sharing is greatly improved across the range, and the need fo fine tune the actuator geometry is eliminated because the integrating term will compensate to achieve good load balance (the actuator still requires an initial set-up at full-speed, no-load). There is a slight trade-off in that the some throttle instability may be introduced which may require tuning out.
Can I mix Integrating and Non-Integrating modules on the same bus?
Emphatically NO. Load sharing will be poor or non-existent, and may even lead to reverse power trips and blackouts.
Can I replace all my modules with integrating types?
Yes you can - but be sure to include spare modules in the change-out. Changing to the newer type will make sourcing replacement spare modules easier and cheaper.
Can I upgrade my modules to the integrating type?
Yes you can - Contrelec has a modification scheme to convert these modules. Contact email@example.com for more details. The down-side is that all modules have to be done at once because you can not mix module types, so the opportunity only arises at planned outages.
Can I convert an integrating module to non-integrating?
Not easily - but Contrelec have a standard modification scheme to achieve this. The down-side is that all modules have to be done at once because you can not mix module types, so the opportunity only arises at planned outages. Contact firstname.lastname@example.org for more details.