Energy Audit Suggestions

I'm trying to do a DIY energy audit of a large church, where I work as a maintenance tech. (mostly in controls). I've been trying to conduct an energy audit, so I can pie chart how much energy is being used by the various circuits/equipment/appliances. I was going to try shutting down all but one circuit on a holiday or at night and take readings off the power meter, but it doesn't seem to display actual current usage, and working off the accumulated usage is impractical. So...

Plan B is to amp/clamp the circuits at the switches and breakers. I started playing with that yesterday, starting with the equipment that I most need data on, one of our large chillers. The switch has three 3-phase (480v, I assume) cables/circuits passing through it, the legs of which circuit bundled and connected together to the three switch terminals.

So I amp clamp the only wire that I can get the clamp around and read almost 30 amps. Assuming that I'm able to get an amperage reading from the other wires, what formula can I use to calculate watts? Do I just use the 30A in a standard power equation (V*A=W), do first I sum the amps of the 3 legs, do I apply a formula to the 3 amp values to get some "effective equivalent" to plug into the power formula?

If it's not that easy, is there a way to do it without hiring a consultant?

Energy Costing

OK, now that this drive is performing adequately, I'm going back to trweaking the controls system to minimize energy costs.

How can I get a feel for the cost difference of running this fan between 0% and 10%, and between 50% and 60%. That is, I need to know how much power is used off schedule when it is running at it's current minimum setting (10%), and what it costs me to increase the duct pressure with a 10% change in frequency (from say 50% to 60%, eg).

single 50 HP SAF is controlled by: Altivar 58 VFD
Drive settings:
460V, 60Hz, 61A, 1760 RPM
mtr cos phi/power factor = .95

single 20 HP RAF is controlled by an ABB VFD
Drive settings:
460V, 60Hz, ??A, 1725 RPM
power factor = ??

What I'm really asking is: "Do VFD driven motors consume power linearally with the frequency?" and is there a formula to get reasonable kW/hr number from the data above?

TIA

Altivar 58 Trips For Overbreaking

I'm probably going to have to call in a pro for this, but would like to see if I can stumble on something simple. I'm overbudget and work for a church, so I'm trying inexpensive DIY-diagnosis first. Unfortunately, I'm not trained in this area. I barely know what a VFD is. But if anyone has some suggestions for things to check, I'm willing to do some self study and decrease my ignorance a little.

We have this large air handler with a pretty good sized return air fan (inline in the return air duct), that is slaved to the supply air fan through code in the building controls (Delta v3). I don't know if the problem is gradually getting worse, or if it's always been an issue and I've just not been paying enough attention. Here's the problem:

During startup or recovering from a fault, about the time the system approaches setpoint (static pressure), the VFD faults for overbreaking (code = Obf). I don't notice any attempt of the drive to slow down, it seems to always still being in the ramp up phase. I can speed it attains before fault, if I sneak up on it (maybe 940 RPM, instead of 809 RPM). The only mods to config that I've done, is to max out the ACC and DEC configs to make the ramps as slow as possible. (They were 150 and 80 for ACC and DEC, respectively, now are set to 999 for both.) This allows me to set a max control signal of 47% instead of 43.8%. This air handler feeds only VAVs (54 of them, about 1/3 of them in use weekdays, about 2/3 of them in use on Sundays). I need to be able to send a control signal of about 55% on the few times when all the VAVs are open.

I would like to get the system modified at some point to hardwire slave the return air fan to the supply air fan, I don't feel like it's a good idea to just send a calling value to both and have the RAF at 45% when the SAF is faulted out or when it's ramping up from 0 after a fault. It's hard on the ductwork. I believe that our other two large AHUs are hardwired.

Here's the data that I have so far:

Trane AHU; single 50 HP SAF, single RAF
SAF is controlled by: Altivar 58 VFD
Drive settings:
460V, 60Hz, 61A, 1760 RPM (this matches the motor data plate)
mtr cos phi/power factor = .95
auto tune = no
Max out freq = 60.1
ramp type = Linear
SwitchRamp2 = 0 Hz (Freq for ramp switching, when output freq > this setting, ramp times will be AC2 & dE2 [which have no values, or at least aren't displayed in the menu] )
DecRampAdapt = no*
TorqueLimit = 200%
CurrentLimit = 107.7 (adj range is supposed to be 0 - 1.35 In) ?????!!??
Deactivation of auto DC injection at stop is allowed
SFt (SwitchFreqType) = LF (allows adj bet 0.5 and 4 kHz using the SFr parameter)
SFr (SwitchFreq) = 2; range depends on SFt; for 2, max op freq = 250 Hz
NoiseReduction = yes (randomly modulates the switching freq to reduce noise)
SpecialMotor = no (extends adj range of IR compensation
Stt (not in manual) = "NST: Freewhl stop"

Ideas? Should I set the DEC adj to a smaller value?

*" 'Activation allows the deceleration ramp time to be auto increased, avoiding an Obf fault if the ramp time was too short. This function may be incompatible with ramp positioning & with dynamic braking. If Relay2 is assigned to BrakeLogic, DecRampAdapt can only be set to "no". (Relay2 is set to "OCC".)'