Hospital Pendants Structural Calculation
Hospital Pendants Structural Calculation
(OP)
Hi,
I m asked to calculate the allowable load for a designed hospital pendant which needs to be mounted on the ceiling.
The company has given me a similar sample to take reference but I have a lot of steps which I don't understand, so sorry there may be a lot of questions I need to ask for...
First, at page 3, Spreading area = (560+2x90)x(311+2x90) = 740x491mm^2
I don't know where are those numbers come from?
And at page 4 about the Restoring moment about edge, I also don't understand the whole step, where 9.8 kN comes from and FS = 14>1.5. Does FS mean Factor of Safety?
And last at page 6, starting from Check Restoring Moment: 3 nos. of M10 HSL
It will be grateful if anyone could explain whole calculation steps.
Thank you for helping
I m asked to calculate the allowable load for a designed hospital pendant which needs to be mounted on the ceiling.
The company has given me a similar sample to take reference but I have a lot of steps which I don't understand, so sorry there may be a lot of questions I need to ask for...
First, at page 3, Spreading area = (560+2x90)x(311+2x90) = 740x491mm^2
I don't know where are those numbers come from?
And at page 4 about the Restoring moment about edge, I also don't understand the whole step, where 9.8 kN comes from and FS = 14>1.5. Does FS mean Factor of Safety?
And last at page 6, starting from Check Restoring Moment: 3 nos. of M10 HSL
It will be grateful if anyone could explain whole calculation steps.
Thank you for helping






RE: Hospital Pendants Structural Calculation
FS typically means Factor of Safety but context within design calculations should be clear
RE: Hospital Pendants Structural Calculation
Restoring Moment - the 9.8 kN is the tension capacity of the anchor. The (0.27 + 0.27) for the 3 anchors should be the moment arm from the anchor tension to the compression centroid (which its not). FS is as you said "Factor of Safety"
Further notes:
First, I am used to seeing 4 to 5 ft of space between the ceiling and the structural soffit above and would recommend dropping your support down to the recommended mounting height suggested by the equipment vendor. This has the added benefit of giving you lots of space to install a nice wide base to support the structure as well as include the lateral braces for the long drop height.
Second, the overturning moment can occur in any direction and, when oriented orthogonally to the plate, is probably not worst case.
Third, for a lightly loaded system such as the MMP90, consider a light gage metal channel framing system (ex. unistrut) - see attached.
RE: Hospital Pendants Structural Calculation