sparco zone valves

Dave Millet_2

We are experiencing our zone valves heating up quite hot to the touch. We're attempting to operate six sparco 525 motorized zone valves w/ end switches from a "H.P.S.' systems pump/circuit board panel w/ the 24 volt auxillary output provided within the panel. The transformer provided is rated 40 watts (va). At this time we don't even have the boiler fired yet since we are still at the purging stage.
Is it normal for the valves to heat up when open? I was told some models heat wax to expand and physically push the valve open. Honeywell, the manufacturer, was unable to provide me with any relevent information. If anyone has any idea on this I would greatly appreciate it.

BillW@honeywell

I wonder who you spoke to at Honeywell???

The Honeywell Water Products Powertrack zone valves don't work by heating wax, although some competitor's valves do. The valves are rack & pinion drive. Over-heating can be caused by too much or too little voltage. Up to eight of these valves can be powered by a 40 VA transformer. Please contact 401 738 4290, press option 7 for further technical support. Thanks for using our products!

Dave Millet_2

Bill,
Thanks for your response. I couldn't tell you who I spoke with from technical support because our connection was so bad I couldn't hear a thing. Like talking to an ant through three foot thick glass.
The strange thing is even with only one valve operated at a time they still heated up. We will trouble shoot with a voltmeter.

Gene_3

VA ratings

This is from my PP for students. It may help others understand VA ratings, don't ask me why they don't just print the amp rating, that would be too easy??

UNDERSTANDING V/A RATINGS ON TRANSFORMERS


TRANSFORMERS ARE RATED IN VOLT-AMPERES OR V/A

THE 24V STEP DOWN TRANSFORMER WE USE IS 40 VA

BY USING A SIMPLE FORMULA WE CAN FIND OUT IF THE TRANSFORMER IS CAPABLE OF HANDLING THE LOAD

DIVIDE THE VA RATING BY THE VOLTAGE OUTPUT

THE RESULT IS THE AMPS RATING

FOR EXAMPLE - 40VA : 24V = 1.66 AMPS

THE TRANSFORMER WILL HANDLE 1.66 AMPS

A 75 VA WILL BE 75 : 24 = 3.12

IF YOU KNOW WHAT YOUR ZONE VALVES DRAW FOR AMPS YOU WILL KNOW HOW MANY YOU CAN SAFELY RUN OFF YOUR TRANSFORMER

YOU WILL ALSO KNOW WHAT SIZE FUSE TO USE TO PROTECT THE TRANSFORMER

TACO CLAIMS YOU CAN RUN 3 ZV’S ON ONE 24V40VA TRANSFORMER


BUT AT .9 AMPS EACH AND TOTAL OF 2.7 IT IS WELL OVER THE 1.66 WE KNOW THE TRANSFORMER IS RATED FOR



WITH TACO ZV’S THE HEATERS CYCLE ON AND OFF SO ALL THE AMPERAGE DRAW IS NOT AT ONCE


HONEYWELL ZV’S PULL .32 AMPS SO YOU CAN RUN 5 OF THEM ON A 40VA WITHOUT A PROBLEM
all low volt systems should have a fuse at the transformer too.

BillW@honeywell

PowerTrack zone valves

Thanks for the explanation, Gene. The .32 rating you mention applies to our standard V8043 series zone valve. The amp draw for the Powertrack valves is .25.