HVAC Supplies Blog

All ACI pneumatic transducers have a fail safe model.

When the installation requires dampers to close quickly on a power failure, or any actuator to assume a fail safe position quickly, ACI has the answer. Look for the FS suffix on ACI pneumatic interfaces.

1. These are not bleed type interfaces. They consume no air at setpoint and require no increase in the size of the compressor. The controlled, high capacity, three-way branch exhaust valve allows the branch line to drop to zero on a power failure.
2. Anodized aluminum manifold with gauge port - gauge can be factory installed.
3. Air handling capacity of 750 scim.
4. Field selectable input ranges.
5. 0 -15 psig output (plus feedback).
6. Manual Override - allows operation checkout before putting in service.
7. Not position sensitive, mounts at any angle, on snaptrack provided.

Product	Signal Action	Features
PXP2.3FS	Analog to Dual Valve Pneumatic	High capacity supply valve, 750 SCIM, 90-100 micron filter-in-barb provided, 3-way branch valve exhausts on power failure, manual override, field selectable signal input ranges
PWP2.3FS	Pulse to Dual Valve Pneumatic	High capacity supply valve, 750 SCIM, 90-100 micron filter-in-barb provided, 3-way branch valve exhausts on power failure, manual override, field selectable signal input ranges
PTS3.3FS	Floating Point to Dual Valve Pneumatic	High capacity supply and branch valve with 3 Min. to max. change rates available on branch, 750 SCIM, 90-100 micron filter-in-barb provided, 3-way branch valve exhausts on power failure, selectable ramping times

See PXP2.3FS

Most any ACI interface or other small control component will fit in this metal box.

The ENC1 is a 20 gauge metal enclosure designed to hold ACT control interfaces or any small HVAC or Building Automation Control component. ENC1 has 2" diameter opening to view gauge, and two 7/8" diameter openings in the ends to accept 1/2" EMT fittings for control and power wiring. Snap in covers on all openings. ENC1 features a light gray powder coat finish cured under high temperatures to seal all enclosure surfaces.

The following interfaces fit the ENC1:

ARM	ATL	ATP	AUD
ISM	PTA	PTA2	PTP
PTS3	PTS4	PWP	PXP
RIM	RTI

 

Other specialized versions of this enclosure available.

See ENC1 Product

ITS LIMITATIONS ARE ITS BEST FEATURE!

The AIM2 (Analog Isolating Module) can be adjusted to LIMIT the OUTPUT signal.

The AIM2 can RE-SCALE the output.

The AIM2 can re-scale the analog current or voltage signal from controller to actuator (or sensor to controller) and provide optical signal isolation.

AIM2 will also limit the output you set. Used commonly for signal connection to variable speed drive controllers or chiller control packages, the AIM2 is very versatile.

Some of the features are:

1. Output range is field adjustable and limited to the highest adjusted value.
2. Solves ground loop problems.
3. 600 VAC optical isolation. 1500 VDC optical isolation.
4. Input and output are selectable for voltage or current.
5. LED's indicate that incoming and outgoing power supply is present.
6. Isolates a signal to grounded electric actuators.
7. Field select direct or reverse acting.

Product	Type	Features
AIM2	Re-scalable optical isolation of an analog signal	24 VAC powered, 3 standard analog input and output ranges, plus adjustable output. Output is "limited". Easy-to-wire 45o terminals.

 

AIM2 is provided with a snap track for mounting, however clips that fasten into the back of the snap track to allow DIN rail mounting can be ordered (DRC Kit).

 

See All AIM2 Products

Need to stage 2 analog devices where the 2nd is needed only if the 1st isn’t enough? We do it from one analog signal?

Here’s how. Using one (1) AIM1, one (1) ARM and a 24 VAC power supply, set up in the following configuration:

AIM1 - Set J1 to 5 VDC, J2 to 10 VDC and J3 to E)

ARM - Calibration should be 5-10 VDC in and 0-10 VDC out Factory calibration is available

Connect your input signal to both AIM1 and ARM. Connect the first controlled device to the AIM1 and second to the ARM. Connect the power supply.

Vin	0	1	2	3	4	5	6	7	8	9	10
Vout1	0	2	4	6	8	10	10	10	10	10	10
Vout2	0	0	0	0	0	0	2	4	6	8	10

ACI made a decision a few years ago to manufacture our electric to pneumatic interfaces with Closed Loop control. They discontinued the open loop pneumatic interfaces primarily because the closed loop offers a better controlled system. ACI closed loop interfaces have been used to replace many other open loop interfaces that were failing from excessive cycling. Commonly the BAS controller in an open loop system periodically gives a refresh command signal to the interface to maintain a specific pressure on the branch line. The closed loop interfaces from ACI react at the transducer to compensate for pneumatic variances on the branch line. If the branch line is severed the closed loop interface will remember the last commanded position and recall the desired pressure output upon reconnecting.

Analogies:

• Open Loop. An automobile with an absolute throttle position at 40 MPH will bog down going uphill but then speed up considerably when going downhill.
• Closed Loop. The automobile will automatically compensate for any steep grade and keep a consistent 40 MPH speed.

The ACI pneumatic closed loop interface accepts a control input signal (voltage, current, pulse width modulation, or floating point) and converts this to a proportional pressure output signal. The interface will continue to maintain the desired output pressure until the input command signal changes. If the control input signal does not change and the branch pressure is not proportional to the pre-calibrated range, the transducer will self correct the pneumatic output to achieve the desired result. If you are having any difficulties with a current system, we suggest that you try one of these interfaces and observe if it corrects the performance of your system.