New Cutler Hammer Motor Control Centers
New Cutler Hammer Motor Control Centers
(OP)
Cutler Hammer now sells their "IT" smart MCC line which features 24VDC control as opposed to the historical 120VAC control via control transformer. Any opinion on this new direction. As far as I can find, they are only vendor offering 24VDC control.





RE: New Cutler Hammer Motor Control Centers
Are they IEC contactors? If so, beware that IEC contactors are rated for many fewer operations than NEMA contactors, it's like an order of magnitude less. I forget the exact numbers, but I want to say 10,000 (IEC) vs. 100,000 (NEMA).
Also, 24 VDC might cause voltage drop problems if your control wiring has to run long distances.
RE: New Cutler Hammer Motor Control Centers
These will be for NEMA style MCC panels as well...
RE: New Cutler Hammer Motor Control Centers
RE: New Cutler Hammer Motor Control Centers
From the Cutler Hammer 2003 Consulting Guide:
Contactor Performance
IEC Type:
Electrical life - 1 million AC3 operations; 30,000 AC4 operations when tested per IEC recommendations
NEMA Type:
Electrical life typically 2.5 to 4 times higher than equivalently rated IEC device on the same test.
Fault Withstandability
IEC Type:
Typically designed for use with fast acting, current limiting fuses.
NEMA Type:
Designed for use with common domestic fuses and circuit breakers.
RE: New Cutler Hammer Motor Control Centers
There are two communications methods. A.) individual devicenet to the starter or B.) QC port which daisey chains the starters together back to an I/O block that converts to devicenet. This allows you to use one node rather than a node per device.
RE: New Cutler Hammer Motor Control Centers
I think it is coming and C-H will not be the only manufacturer offering this.
RE: New Cutler Hammer Motor Control Centers
1-They are being offered to reduce panel space (contactors are extremely small, probably 30-40 percent smaller than comparable IEC contactor. This size reduction is due primarily to the reduction in size of the coil.
2- They have potential but not necessarily advantages in remote control.
3- Safety perhaps but very little advantage by my thinking.
4- Larger power supply will be required if you already have one, if no DC power supply then you will have to add that into the cost.
We decided against (at this time) because we see no advantage in most of our products, and because we are making it difficult for a customer to get replacement for their equipment locally.
PUMPDESIGNER
RE: New Cutler Hammer Motor Control Centers
I think that there is a distinct disadvantage to the additional complexity of the 480VAC-24VDC switch mode power supply over a simple control power transformer. The additional risk of failure and additional heat is unwarranted for the benefits recieved.
Quando Omni Flunkus Moritati
RE: New Cutler Hammer Motor Control Centers
We already have a power supply, and adding that contactor into our panel is still not desirable because we have to upsize our power supply.
Just one more component to have a problem.
PUMPDESIGNER
RE: New Cutler Hammer Motor Control Centers
RE: New Cutler Hammer Motor Control Centers
Thanks