724-746-5500 | blackbox.com
724-746-5500 | blackbox.com
Page 19
Chapter 4: Maintenance
ATTENTION: If water drips from the air-purging valve after you remove the air-purging tool, reattach the tool and disconnect it
again to exercise and seat the seal.
5. With one end of the air-purging tool inside the bucket, attach the other end of the air-purging tool to the rightmost (return)
air-purging valve. As the air-purging tool is screwed on to the valve, water that is mixed with air will begin to spit into the
bucket. When there is a steady stream of water from the air-purging tool into the bucket, unscrew the air-purging tool from
the valve.
NOTE: Air in a coil causes a splashing or gurgling sound. Repeat the air-purging procedure on both valves if this sound is present.
6. Screw the valve caps onto the air-purging valves and hand-tighten them to provide a secondary seal.
4.2 Draining the HTD
Perform this procedure before having the HTD removed from the IT enclosure or when directed to do so by Black Box Technical
Support. The drain port is at the bottom of the HTD, near the supply and return couplings (see Figures 4-1 and 4-2).
CAUTION: Wear safety goggles or other eye protection whenever filling, draining, or purging air from the HTD.
NOTE: Water exposure not likely, but you might prefer to place some water-absorbent material beneath the HTD as a general
practice when draining the HTD.
To drain water from the HTD, complete the following steps.
1. Shut off the flow of water to the HTD at the source.
NOTE: Depending on your facility, this might mean turning off the CMS unit, closing a valve at the CMS unit, or a similar action.
2. Open the Heat-Transfer Door assembly so it’s at a 90° angle from the enclosure.
3. Disconnect the return hose and the supply hose from the HTD and move them out of the way.
4. Remove the valve caps from the air-purging valves (on bottom-feed models only) and from the drain port.
5. Place one end of the long hose of the air-purging tool into a bucket (minimum 1.5 gallons/5.7 liters capacity) to catch the
water that escapes during the draining procedure.
6. Attach the other end of the long hose to the drain port. As the air-purging tool is screwed on to the port, water that is mixed
with air will begin to spit into the bucket.
7. Attach the 6”/16-cm extension hose to one of the air-purging valves at the top of the HTD (on bottom-feed models only) to
allow air to enter the manifolds.
NOTE: Instead of using the 6”/16-cm extension hose, if filtered and oil-free compressed air is available, you can attach the
compressed-air hose to the air-purging valve to force water out of the HTD. Keep the air pressure at 50 psi (3.4 Bar) or
less to avoid excessive spray at the drain port.
8. When the water flow at the drain port stops, move the 6”/16-cm extension hose or compressed-air hose to the other
air-purging valve (on bottom-feed models only) and repeat the process.
9. When the water has drained completely from the coil, complete the following steps:
a. Remove the 6”/16-cm extension hose or compressed-air hose from the air-purging valve.
b. Remove the long hose from the drain port.
c. Screw the valve caps onto the air-purging valves (on bottom-feed models only) and drain port valve and hand-tighten them to
provide a secondary seal.
4.3 Removing the HTD
Perform this procedure before removing the HTD from the IT enclosure or when directed to do so by Black Box Technical Support.
CAUTION: We recommend that two people attach the HTD to the hinges to prevent the HTD from falling down.
